A ladder having a length of m,
its upper edge is on a vertical wall, and its other edge is on a horizontal floor.
If is the projection of the point on the surface of the floor, and its angle of slope to the surface of the floor is ,
find the length of .
Use the information given to draw , which is a
right-angled triangle. In the figure , , and . This means that the ratio
of the lengths of the triangle's sides is .
Find the length of as follows:
Thus, the length of is m.