"Published in Suisun City, California, USA"
The lower right-hand corner of a long piece of paper 6 in. wide is folded over to the left-hand edge as shown. The length L of the fold depends on the angle θ. Show that
 |
| Photo by Math Principles in Everyday Life |
Solution:
Consider the given figure above and label further using the principles of Plane Geometry, we have
 |
| Photo by Math Principles in Everyday Life |
By Pythagorean Theorem,
We need to use another equations in order to eliminate x and y. By using trigonometric functions of right triangles, we have
Using a small right triangle
Using a large right triangle
Consider again the equation,
Substitute the values of x and y, we have
Take the square root on both sides of the equation, we have
Therefore,
