Question

A viewfinder has a triangular lens. Some of the measurement of the length are shown below. Which of the following best represents the length of a?

Answer 1

Answer:

A

Step-by-step explanation:

First, we need to find the unknown angle of the triangle.

40 + 20 = 60

180 - 60 = 120

So the unknown angle is 120.

Then, we can use the law of sines to create a proportion.

sin(120)/8 = sin(40)/a

Then, we can simplify this.

a is about 5.9, or answer choice A.