Bu using Pythagoras theorem
(x^2)+(21)^2=(75)^2
Therefore. 5625-441=(x)^2
X^2=5184
Therefore x=72
Third side length=72 units
Answer: 42 feet
Step-by-step explanation:
P-area of field
P=2100sqf
a-length of field
a=50 feet
P=a*b
2100sqf=50*b
b=2100/50
b=42 feet