The angle at which builder builds a ramp is 10 degrees
The horizontal span is 75 feet.
When we draw, we get a right angled triangle with its adjacent side as 75 feet and we have to calculate the length of the ramp which is the hypotenuse. Let us assume this to be "x" . Please refer to the attached figure.
Now, we know that the cosine of an angle = adjacent side/hypotenuse side
cos 10 = 75/x
x = 75/cos 10
x = 75/0.984807753
x = 76.1570 Feet
The actual ramp will be 76.1570 Feet