A holding pen for cattle must be square and have a diagonal length of 84 84 meters. a. find the length of a side of the pen. b. find the area of the pen.

we know that
Applying the Pythagoras Theorem
c²=a²+b²
in a square
a=b
c is the diagonal-----> 84 m
c²=2a²--------> a²=c²/2-----> a²=84²/2-----> a²=3528-----------> a=√3528 m

the answer part a) is
√3528 m or 59.40 m



the area of the pen is a²------> 3528 m²

the answer Part b) is 
3528 m²