The answer is 40 yd.
Step-by-step explanation:
50 yards is the hypotenuse.
So,
a^2+ b^2=c^2
a^2+30^2=50^2
Solve the exponents
a^2+900=2500
Subtract 900 from both sides
a^2= 1600
Opposite of squared is square root so find the square root of 1600.
a=40
a is the missing side length
If you wish to prove this stamens simple plug 40 into a in the original equation like so:
40^2+30^2=50^2
Solve exponents
1600+900=2500
Solve
2500=2500
Since the statement is true the answer is correct.