Show that the area of triangle DEF is 11 cm2.​

Show That The Area Of Triangle DEF Is 11 Cm2.

Answers

Answer 1

9514 1404 393

Explanation:

The length CD can be found from the Pythagorean theorem.

  CF² + CD² = DF²

  2² + CD² = (2√10)²

  CD² = 40 -4 = 36

  CD = √36 = 6

From here, any of several methods could be used to find the area of ΔDEF.

One of them is to subtract the areas of the triangles that are not ΔDEF from the area of the rectangle ABCD.

  area ABCD = bh = (6 cm)(5 cm) = 30 cm²

  area ΔADE = 1/2bh = 1/2(4 cm)(5 cm) = 10 cm²

  area ΔBEF = 1/2bh = 1/2(2 cm)(3 cm) = 3 cm²

  area ΔCDF = 1/2bh = 1/2(6 cm)(2 cm) = 6 cm²

Then the area of interest is ...

  area ΔDEF = area ABCD -area ΔADE -area ΔBEF -area ΔCDF

  area ΔDEF = (30 -10 -3 -6) cm²

  area ΔDEF = 11 cm²

__

Alternate solution

If we define A as the origin of a coordinate system, then the coordinates of the vertices of ΔDEF are ...

  D(0, 5), E(4, 0), F(6, 3)

The area can be computed as half the absolute value of the sum of the determinants of 2×2 matrices consisting of adjacent points.

  [tex]A=\dfrac{1}{2}\left|\left|\begin{array}{cc}0&5\\4&0\end{array}\right|+\left|\begin{array}{cc}4&0\\6&3\end{array}\right|+\left|\begin{array}{cc}6&3\\0&5\end{array}\right| \right|\\\\=\dfrac{1}{2}|(0-20)+(12-0)+(30-0)|=\dfrac{1}{2}(22) = \boxed{11}[/tex]

_____

Additional comment

The solution using coordinates is effectively equivalent to the computation of the area of trapezoid ABFD, less the areas of triangles EBF and AED.


Related Questions

Alec types
3
5
of a paragraph in
2
3
minute. If he continues at the same rate, what fraction of a paragraph can Alec complete in 1 minute?

















































































































































































































Alec types
3
5
of a paragraph in
2
3
minute. If he continues at the same rate, what fraction of a paragraph can Alec complete in 1 minute?

Answers

Answer:

He can type 4.5/5 of a paragraph

Step-by-step explanation: Because there are 60 seconds in a mintune right. 2/3 of an hour=40 seconds. 1.5/5=20 seconds and 60 seconds=4.5/5

What is the distance between the points (12, 6) and (−8, 6) on a coordinate plane? *
4 units
12 units
6 units
20 units

Answers

Answer:

im pretty sure it is "4 units"

Step-by-step explanation:

Help me with this pls

Answers

Answer:

C

Step-by-step explanation:

What is m∠1 ? I need help.

Answers

Answer:

*update* 99

Step-by-step explanation:

Carla e Ana foram tomar sorvete e gastaram r$ 23,00 dividido a conta em partes iguais, quanto cada uma pagou ? Gente me explica como faz a conta não só resposta por favor

Answers

Answer:

each of them has to pay $11.5 individually

Step-by-step explanation:

The computation of the amount paid by each one is shown below:

As carla and Ana gone for an icecream and the bill is $23 that should be divided equally

So here the carla should pay

= $23 ÷ 2

= 11.5

And, Ana should pay

= $23 ÷ 2

= $11.5

Hence, each of them has to pay $11.5 individually

Estimate the line of best fit using two points on the line.

A. y= -3/2x + 12
B. y= 3/2x + 12
C. y= -2/3 + 12
D. y= 2/3 + 12

Answers

Answer:

?

Step-by-step explanation:

Answer: c

Step-by-step explanation:

A p e x

plz help i can not figure this out

Answers

Answer: 30 cubic units

Step-by-step explanation:

Since the base has a volume of 2x3 or 6 and he plans on making the height 5 we must mutliply the base by height to get the new voulme so 6*5=30

Answer:30 cubic units

Please help as quickly as possible, this is Algebra 1!

Answers

Answer:

First-term is 7

The second term is 14

and the third term is 28

i think so im not 100%

A bag contains 42 red, 45 green, 20
yellow, and 32 purple candies. You
pick one candy at random. Find the
probability that it is green or yellow.

Answers

Answer:

65/139 fraction form

0.47 decimal form

Answer:

Step-by-step explanation:

Total sample space , n (s) = 139

no of green candies , n (g) = 45

no. of yellow candies , n (y) = 20

Probability that is green or yellow is

P( g or y) = P(g) + P(y)

               = n(g) / n(s) + n (y) / n(s)

               = 45 / 139 + 20 / 139

               = 65 / 139

hope it will help :)

PLZ I NEED HELP
i really need help on this or i will fail!!!

Answers

Answer:

A

Step-by-step explanation:

A

If you have the point (3,5) x = 3 and y = 5
x + 1 = 3 + 1. 3 + 1 = 4
The point (4,5) is one unit to the right of (3,5) so (x+1,y) would move one to the right

Questions:
PQ is a straight line.
Diagram NOT
accurately drawn
(126% )
(a)
Work out the size of the angle marked xº.
(b) (i) Work out the size of the angle marked yº.
Give reasons for your answer.

Answers

Answer:

the answer is up u can see it if u want explanation u can message me here

It angle relationship and show work??

Answers

Answer:

m<x=146

Step-by-step explanation:

its a supplementary angle, meaning both angles add up to 180.

So we subtract 34 from 180 which is 146.

180-34=146

The equation 7h=63 can be used to find how many hours h a person needs to work to earn $63 at $7 per hour. How many hours does a person need to work to earn $63?

HELPPP ME QUICKLY I HAVE TO SHOW MY WORK ALSO

Answers

Answer:

The equation 7h=63 can be used to find how many hours h a person needs to work to earn $63 at $7 per hour. How many hours does a person need to work to earn $63?

Step-by-step explanation:

The equation 7h=63 can be used to find how many hours h a person needs to work to earn $63 at $7 per hour. How many hours does a person need to work to earn $63?

Answer:

9 hours

Step-by-step explanation:

7h=63

divide both sides by 7 to get 9

7h/7=h

63/7=9

h=9

PLEASE ANSWER
What is the perimeter of the parallelogram?

Answers

Answer:

Perimeter = 44.8

Step-by-step explanation:

Perimeter = 2(13.4 + 9) = 44.8

In a survey of 3,200 people who owned a certain type of car, 1,920 said they would
buy that type of car again. What percent of the people surveyed were satisfied with the car?
% of the people surveyed were satisfied with the car

Answers

Answer: 60%

Step-by-step explanation: 1920/3200=.6  .6 in a percentage is 60%

hey guys its my bday and i don't have time to do work rn but I need the answer for this. I will give brainly away

Answers

SAS, SSS, SSA all prove the congruency of the two triangles.

Do you ever subtract using the z-score?

A) yes
B) no
C) sometimes

Answers

C sometimes, It seems to be completely arbitrary when one must subtract the z-score table value from 1. ... So that's great if you want the left tail of a distribution, but if you want a right tail then you need to calculate the left tail and subtract it from 1 (which is the area of the entire standard normal curve).

t/12 = 4
solve for the solution

Answers

T/12=4
Then t=12*4=48

The following can be decomposed in ????

Answers

Answer:

Triangle & semicircle

Step-by-step explanation:

Write two numbers that multiply to the value on top and add to the value on bottom.

Answers

Answer:

14+9 14×9that is the answer

Help due in 15 mins!

Answers

Answer:

Step-by-step explanation:

1

Proving Two Triangles Are Congruent: What additional is needed to prove that ABC = DBF using the SAS congruence theorem?

Answers

Answer:

the answer is the side length of ab and db

Answer: D on edge

Step-by-step explanation:

How far up the house would a ladder be resting if it is 25 ft long and 3 ft
away from the house? Round to the nearest tenth if necessary.
5.3 ft
21 ft
24.8 ft
25.2 ft

Answers

Answer:

C

Step-by-step explanation:

The last one is absurd. You can't have a ladder reaching higher than itself. The question is a Pythagorean problem.

Givens

a = 3

b = ?

c = 25 feet

Formula

a^2 + b^2 = c^2

Solution

3^2 + b^2 = 25^2

9 + b^2 = 625                  Subtract 9 from both sides.

b^2 = 625 - 9

b^2 = 616                        Take the square root of both sides.

b = sqrt(616)

b = 24.8

Please answer this correctly and do not guess or put random stuff. I will report if you do so.

Answers

Answer: y=8x

Explanation: The graph shows a linear relationship.

The following are the ages (years) of 5 people in a room:
17, 21, 15, 15, 25
A person enters the room.
The mean age of the 6 people is now 25.
What is the age of the person who entered the room?​

Answers

Answer:

57 years

Step-by-step explanation:

total=25*6=150

17+21+15+15+25+x=150

93+x=150

x=150-93

x=57

Answer:

age=57

Step-by-step explanation:

ages=17 21 15 15 25 ?

17+21+15+15+25=93(old mean)

17+21+15+15+25+?=25(new mean)

25(new mean)*6(number of numbers)=150

?=150-93=57

= 57

6) Find the value of x.
AKLM-ACDE
4x + 5
E
D
55
L
132
108
M M
K

Answers

Answer:

55 ? i think

Step-by-step explanation:

i just had the same question

A truck travels 333 km in 6 hours. What is the truck’s speed for that trip?

Answers

Answer:

55.5 km

Step-by-step explanation:

speed=distance/time

55.5= 333/6

Answer:

55.5 km per hour

Step-by-step explanation:

The simple formula is D_S-T

D is at the top for Distance

S is down to the left for speed

And T to the right as Time

Its simple so just take

Distance: 333km

Time: 6 hrs

333÷5=55.5/1

Is 2,-2,3,-2,7,-2,11,-2 a function

Answers

Answer:

Step-by-step explanation:

D

Write the recursive formula for this sequence: 3, 1, -1, ... *

Answers

Answer:

the answer is 5-2n please do you get it

HELP ILL GIVE BRAINLIEST what shape is the base??

Answers

Answer:

rectangle

Step-by-step explanation:

it's width is 6

it's length  is 12

it couldn't be a square

Other Questions
why couldnt Tom Robinson have grabbed Magellan by his left hand? Which phrase best describes Thomas Paine's vision for America?starting overfighting religionhonoring traditiondeveloping strength Will mark Brainliest! What is the value of P. Thank you! A sphere has a volume of 36(pi) in^3. What is the surface area in terms of Pi Please answer! Just choose A, B, C or D. Harrison Forklift's pension expense includes a service cost of $26 million. Harrison began the year with a pension liability of $46 million (underfunded pension plan). 1. Interest cost, $7; expected return on assets, $20; amortization of net loss, $6. 2. Interest cost, $22; expected return on assets, $16; amortization of net gain, $6. 3. Interest cost, $22; expected return on assets, $16; amortization of net loss, $6; amortization of prior service cost, $7 million.Required:Prepare the appropriate general journal entries to record Harrison's pension expense in each of the above independent situations regarding the other components of pension expense ($ in millions). Officer Belkin stopped Stephen on the street after observinghim engaged in what appeared to be the sale of illegalnarcotic drugs. The officer observed the typical behavior thattakes place when someone asks if drugs are available andwhen drugs and cash are exchanged, although the officer didnot see any actual drugs exchanged. When asked what hewas doing, Stephen replied, "just chillin'."Assume that the initial stop of Stephen by Belkin was valid.Which one of the following may Officer Belkin do withregards to a search of Stephen?A)Belkin can conduct a full search of StephenB)Belkin cannot frisk or fully search Stephen because he does nothave probable causeC)Belkin can frisk Stephen, looking for drugsD)Belkin can frisk Stephen, looking for weapons I got 49 will someone double check me please?! Characterize Nat Field from the book King of Shadows PLEASE HELP HELP what's the distance for this question? The red shift of light from most galaxies is evidence that What is sinK?A. 12/13B.13/12C.5/13D.5/12 Some organisms reproduce sexually. Other organisms reproduce asexually. What are some benefits of asexual reproduction?A. It benefits organisms that that are immobile.B. It gives offspring the genetic traits to survive in a particular environment.C. It uses less energy.D. All of the above. Help please! Write the sentences in Spanish. I need help fast!!!!!! james has a recipe that calls for 6 cups of sugar he wants to use only 1/2 of the recipe today how much sugar will he need do you multiply or divide Could someone pls help me what is the product of the Trinomial and the Binomial below(x2+5x-2)(x-3) B. Now, assume that all of these circles have a radius of two. Then, calculate the ratio of a proximate circumference to the diameter. You would like to have $10,000 in an account after eight years time. If the account earns 2.5% compounded interest yearly, how much would you have to deposit today