Answer:
9/12 = 4/x
Step-by-step explanation:
The height of the larger triangle is 9. The base of the larger triangle is 12. So let's make the ratio 9/12.
The height of the smaller triangle is 4. The base of the smaller triangle is x. So let's make the ratio 4/x.
Since both triangles are congruent, let's make these both equal each other to solve for x (if you need to).
Thus, it's 9/12 = 4/x.
