In the triangle below x= ? cm. Round to the nearest tenth
When refering to the 20o angle, the 10 cm side is the adjacent and y is the hypotenuse.
Since cos = adj/hyp cos(20o) = 10/y
Multiplying by y: y · cos(20o) = 10
Dividing: y = 10 / cos(20o)
Now, it's up to you and your calculator ...