Question

http://roads.advancedacademics.com/contentserver/content/roadssection/292253//right%20triangle%20abc%20with%20right%20angle%20c.%20%20leg%20cb%20=%204%20and%20hypotenuse%20ab%20=%205.png

Answer 1

What do you want to do with this triangle?

Answer 2

find angle A

Answer 3

Do you have any idea which trigonometry function to use?

Answer 4

i really dont

Answer 5

We should use sine in this case as sine is equal to \(\frac{\text{Opposite}}{Hypotenuse}\). The opposite side is relative to the angle you are finding. As we are now finding angle A, the opposite side is BC.

Answer 6

after having 4 over 5 what do i do

Answer 7

Lets call angle A theta.
\[
\begin{align*}
\theta&=\angle\text{CAB} \\\\
\sin{\theta}&=\frac{4}{5} \\
\arcsin\sin{\theta}&=\arcsin \frac{4}{5} \\
\theta&=\arcsin\frac{4}{5}
\end{align*}
\]
Complete the answer by yourself.
P.S. arcsin is sometimes known as \(\sin^{-1}\).

Answer 8

how do you calculate the \[\left(\begin{matrix}4 \\5\end{matrix}\right)\]

Answer 9

What is that? The binomial function?

Answer 10

sory i ment to put 4 over 5

Answer 11

Sine is \(\frac{\text{Opposite}}{\text{Hypotenuse}}\). The opposite of angle A is BC=4. The hypotenuse of the triangle is AB=5. Therefore \(\frac{\text{Opposite}}{\text{Hypotenuse}}=\frac{4}{5}=\sin\angle \text{A}\)

Answer 12

but my answer choices are these ?A. 60
B. 53
C. 45
D. 37

Answer 13

Don't forget to arcsin it. \(\arcsin \frac{4}{5} \neq \frac{4}{5}\).

Answer 14

so then?

Answer 15

Bring out your calculator and calculate arcsin(4/5)!

Answer 16

i dont have a calculator like that sorry i just have a simple one

Answer 17

*facepalm*
It is equal to 53.13010 degrees.

Answer 18

thanks i really apreciate it