Question

Sarah walks 20 feet away from her house and places a mirror on the ground. She backs up 5 feet away from the mirror so that she can see the tip of the roof. Sarah's eyes are 4 feet above the ground. The angles between the top of the house, the mirror, and the ground between Sarah's eyes, the mirror, and the ground are congruent as shown in the image:

Part 1: prove the triangles are similar
Part 2: determine the height of the house

Answer 1

It's upside down.

Answer 2

It isn't for me..

Answer 3

@Mertsj could you help me though?

Answer 4

@TachiHere could you help me ?

Answer 5

@pyrohair

Answer 6

The triangles are similar by AA similarity.

Answer 7

Can u explain why?

Answer 8

Because 2 angles of one triangle are congruent to 2 angles of the second triangle. That's what AA similarity means.

Answer 9

Okay what is the height of the house?

Answer 10

\[\frac{20}{5}=\frac{x}{4}\]

Answer 11

.??????

Answer 12

I don't understand how to do that.

Answer 13

cross multiply.

Answer 14

Is the answer 14?

Answer 15

no

Answer 16

Then what?
Could u explain it better?

Answer 17

What do you get when you cross multiply?

Answer 18

X/20??

Answer 19

Do you know what cross multiply means?

Answer 20

60?

Answer 21

Do you know what cross multiply means? This is a simple yes/no question.

Answer 22

Yeah

Answer 23

Then what do you get when you multiply 5 times x?

Answer 24

5x?

Answer 25

What do you get when you multiply 4 times 20?

Answer 26

80

Answer 27

Then write 5x=80 and solve.

Answer 28

Is it 16?

Answer 29

yes