Thanks for your questions. Your problem was –
Find out the area of the figure with all its sides equal in length if it is given that the perimeter of this regular polygon is 100.

I’m trying to solve your problem and explain in details.  now let’s see –

Your question’s details Explanation:
According to the question, the figure is having all its sides equal in length.
From this we can conclude that the given geometrical figure is a square.
Now, it is given that the perimeter of the square is 100 units.
And, perimeter of a square = sum of all its sides
Since, all its sides are equal in length, we can say that perimeter of the square = 4(side)
= 100
∴ Side = 100/4 = 25
Now, we have to find out the area of the square.
Area of a square = side * side
∴ Area of the square with side 25 units = 25 * 25 = 625 square units

Hope you can understand easily. If this is useful for you, then share to your friends. and visit from my website Knowledge World
Thanks.