Your distance from where the 50-yard line intersects the sideline is: 50 yards
How to solve the direct ratio?
We are told that:
Your seat at a football game is directly in front of the 10-yard line, 30 yards from the field.
Your position forms congruent angles with the 10-yard line, the 25-yard line, and the 50-yard line as shown in the figure.
Using the concept of direct ratio for congruency, we have:
30/15 = x/25
where x is your distance from where the 50-yard line intersects the sideline.
Thus, cross multiply to get:
x = (30 * 25)/15
x = 50 yards