How high is a 40-foot ramp if it is propped at a 30 degree angle?

This is the concept of trigonometry, the height of the ramp will be given by:

sin theta=[opposite]/[hypotenuse]

theta=30

opposite=x

hypotenuse=40 ft

hence;

sin 30=x/40

thus;

x=40sin30

x=20 ft

the ramp is 20 ft high