Answer:
x = 42
Explanation:
Let the length of the indicated side be represented as "x".
The Theorem of proportionality can be extended and applied to find the indicated side.
Thus, based on the theorem, it is assumed that the parallel lines divides the transversals proportionally.
This implies that:
x/(77 - x) = 30/25
x/(77 - x) = 6/5
Cross multiply
x(5) = 6(77 - x)
5x = 462 - 6x
Add 6x to both sides
5x + 6x = 462
11x = 462
x = 462/11
x = 42