Question

PLEASE HELP - In triangle ABC, A is a right angle and mB = 45°. Find BC. If your answer is not an integer, leave it in simplest radical form. The figure is not drawn to scale.

Answer 1

12 ft
12 ft
24 ft
24 ft

Answer 2

@.Sam.

Answer 3

uh well do you know how a 45-45-90 triangle works?

Answer 4

No...

Answer 5

Okay well you don't need that. Do you know how the pythagorean theorem works

Answer 6

Yeah, a^2+b^2=c^2

Answer 7

Okay well if mB = 45, and mA = 90, then you can use the fact that the angles of a triangle must add up to 180 degrees to find mC

mC = 180-(90+45) = 45

Since mC = mB, triangle ABC is an isosceles triangle. So, AB = AC = 12.

Now you can use Pythagorean Theorem to find BC

AB^2 + AC^2 = BC^2
144 + 144 = BC^2
BC = 12sqrt(2)

Answer 8

Oh okay. See, I didn't know how to find the other side.

Answer 9

hmm? well does it make sense now. Would you like me to show you how a 45-45-90 triangle behaves?

Answer 10

Yeah, it kinda makes sense. And yeah, if it will help me understand better lol. Can I show you this other problem? It's sort of similar.

Answer 11

Find the value of the variable(s). If your answer is not an integer, leave it in simplest radical form. The figure is not drawn to scale.

Answer 12

okay I was trying to draw a 45-45-90 triangle but then I gave up

here's a link http://www.atlantic.k12.ia.us/~period5/images/45-45-90_triangle.jpg

um okay let me look at the next problem

Answer 13

yeah that's a 30-60-90 triangle, have you learned about those?

Answer 14

If not, then you can use pythagorean theorem again

Answer 15

I've learned about triangles, but I never learned about 30 60 90 or the other triangle.

Answer 16

I know the pythagorean Theorem.

Answer 17

okay well then just use pythagorean theorem. The triangles I'm referring to are just shortcuts.

here's a link for a 30-60-90 triangle for future reference http://www.atlantic.k12.ia.us/~period5/images/30-60-90_triangle.jpg