How do you change 1/10 into a while number

A. tan 42° = y/115

Step-by-step explanation:

Let's imagine there is a triangle here. We have the angle (42°) of the triangle and the adjacent side length(115 meters). We are trying to find the height of the lighthouse(opposite side of the triangle). It is tan that uses adjacent and opposite length, not cos. The calculation will be:

tan x= opposite/adjacent

tan 42° = y/115

y= 0.90 * 115

y= 103.5 meter