I need the answer ....

Answer:
12.5 feet
Step-by-step explanation:
how to:
lets find the angle that corresponds with the 10 foot side.
to do that we add 50 degrees plus 90 degrees (right angle) to get 140 degrees.
as we know, a triangles angles will total 180 degrees, so 180 - 140 = 40 degrees for the angle corresponding to the 10 foot side.
put these into ratios:
Angle A = Angle B
side a side b
now plug in our numbers:
50 degrees = 40 degrees
X 10 feet
Cross multiply:
50 (10 feet) = 40 (x)
solve for x:
500 = 40 (x)
500/40 = x
12.5 = x