A10-foot ramp must make an angle of 30° with the ground if it is to reach a certain window. what angle must a 15-foot ramp make with the ground to reach the same window?

In solving problems like this, it's best to work on a diagram (see attached image). First, given the angle formed by the ramp and the length of the ramp, we can apply the properties of right triangles and recall that 



Hence, we have





Now that we have the window's height, we can compute for the angle, θ, if the ramp has a length of 15.





Therefore, for the 15-foot ramp to reach the window, the ramp must form an angle of 19.47°.

 19.47°