Answer:
Explanation:
Remark
- x is opposite the 90 degree angle. It is the hypotenuse.
- 13 makes up the 57 degree angle. It is the side adjacent.
- The adjacent side and the hypotenuse define the cos(theta).
Formula
cos(theta) = adjacent side / hypotenuse
Givens
Theta = 57 degrees
Hypotenuse = x
Side adjacent = 13
Solution
- Cos(57) = 13 / x Multiply both sides by x
- x*cos(57) = 13 Divide by cos(theta)
- x = 13/cos(57)
- x = 13 / cos(57)
- cos(57) = 0.5446
- x = 13/ 0.5446
- x = 23.87