Question

I need help with triangles!!

Answer 1

Find the missing lengths in the triangle. Round to the nearest tenth if necessary.

a = 7.5 cm, b = 10.6 cm
a = 13 cm, b = 7.5 cm
a = 7.5 cm, b = 13 cm
a = 5 cm, b = 13 cm

Answer 2

Any help is good!! :)

Answer 3

Can you tell me what you've tried so far?

Answer 4

Well I am not really sure how to solve it so I took a wild guess and chose the last option. [D]

Answer 5

Ok, are you learning how to use trig functions? Sine, cosine, and tangent?

Answer 6

I started to, then I got sick and I have been out of school for almost a week and the teacher sent me papers with these questions on them that I haven't really learned..

Answer 7

Ok, I'll explain them :)

Answer 8

Thank you!

Answer 9

Sine of an angle is equal to the opposite side from that angle divided by the length of the hypotenuse
Cosine is the length of the adjacent side divided by the length of the hypotenuse
Tangent is the length of the opposite side divided by the length of the adjacent side

Answer 10

So, they hypotenuse is 15... but there isn't any other side measurements?

Answer 11

Right, but they give you the measurements of the angles, so you can set up equations that only have one unknown

Answer 12

I'll show you one if you want

Answer 13

Please do!

Answer 14

\[\sin 60=b/15 \]
\[.866=b/15\]
\[b=13\]

Answer 15

b is the side opposite of the 60 degree angle, so sin of 60=b/15 (sin is opposite/hypotenuse)

Answer 16

okayyyyyyyyyy........

Answer 17

Do you have a calculator for finding sin/cos/tan of angles?

Answer 18

Yes I dooo actually

Answer 19

That's good :). Do you want to try finding side a? I'll help you if you need anything

Answer 20

I could try but I still dont really know how to find a.... [sorry it's being sick that's talking] :P

Answer 21

It's ok, I'll walk you through it. Which angle do you want to use? You can use the 30 or 60 degree side (you never use 90 degree angles for finding sin/cos/tan)

Answer 22

30?

Answer 23

Ok, so we're using the 30 degree angle and are trying to find the length of the side opposite from it. We also know the length of the hypotenuse. Which trig function should we use?

Answer 24

cosine?

(im sorry to do this but I need to sort of speed this up because I need to get off like in a few minutes

Answer 25

Ok, I'll explain and you can read when you have more time. We actually use sin again because sin is opp/hyp. Sin of 30= .5, so a=7.5. I'll write the equations out

Answer 26

\[\sin 30=a/hyp\]
\[.5=a/15\]
\[7.5=a\]

Answer 27

oh okay thankss

Answer 28

You're welcome, good luck