This document provides instructions for solving for the length of a shared side (x) of two triangles. It instructs the user to write two equations, one for each triangle, relating the lengths of the sides including x. It also describes an approach for solving when the triangles form one large non-right triangle, which is to draw the altitude splitting it into two triangles and using the fact that triangle angles sum to 180 degrees. The user is then told to solve the two equations to find the value of x.

2. Write an equation to solve for the
length of the shared side.
Re-label your sides, and write a
2nd equation to solve for x.

6. When it looks like one big
(non-right) triangle:
Draw the altitude up the middle.
Split up and label top 2 angles if
needed.
Remember: Triangles contain 180°!
Solve like before.

7. Solve for x.

8. Solve for x.

9. Solve for x.