The formula for cos is cos= opposite/hypotenuse. So you look for the length measure opposite the angle, and the triangle’s hypotenuse. To do this, you will find the unknown angle as the possible of said angle is x.
180-90-42
=48
Cos (48) = 17.49/x
— Multiply both sides by x
x • cos(48) = 17.49
— divide both sides by cos(48)
x= 17.49/cos(48)
Plug into a calculator and simply to the nearest thousandth.
x = 26.138
