Question

In ∆ABC, ∠C is a right angle, what is the measure of x?

Answer 1

How did you try solving it?

Answer 2

cos(B) = Adjacent / Hypotenuse
cos(B) = BC / AB
cos(B) = 28.3/66.4

Answer 3

Yeah so thats correct..you can refer to trigonometric tables also

Answer 4

My answer choices are:
42.1
64.8
23.1
25.2

Answer 5

Did you do an arccosine of that?

Answer 6

I'm confused on how to finish solving it.

Answer 7

\(\cos\theta=n\implies\theta= \cos^{-1}(n)\)

Answer 8

You would use COS when you KNOW the measure of the angle...you use COS^-1 when you NEED the measure of the angle...so

instead of cos(B) = 28.3/66.4
do

arcos(B) = 28.3/66.4

Answer 9

Sorry *edit* Arccos(28.3/66.4) = Angle

Answer 10

\(\cos (B) = 28.3/66.4\implies \measuredangle B =\cos^{-1}(28.3/66.4)\)

Answer 11

How do I solve that?

Answer 12

On your calculator, is there an arccos function?

Answer 13

I got 64.77 So my answer must be 64.8 :)

Answer 14

Yep!

Answer 15

Thank you!