Question

Don’t understand. I’ve tried to do it and I need some help please.

Answer 1

You need to use trigonometry
1. Tan37=x/2.1
1.58=x

Answer 2

Remark
It is a calculator problem. All you have to do is make sure your calculator is set to degrees. 

Definition
The Tangent is defined as

Tan(A) = opposite side / adjacent Side

Givens
A = 37°
adjacent = 2.1
opposite = ???

Sub and solve
Tan (37) = 0.75335
0.75335 = x / 2.1 Multiply both sides by 2.1
2.1 * 0.75335 = x
x = 1.58246  <<<<< answer

NOTE NOTE NOTE NOTE NOTE: NO DECIMAL. 
If there is no decimal between the 2 and the 1 in 2.1 then the answer is
15.246 No Decimal <<<<< ANSWER.