Answer:
The area of the playgrounds will be 441 sq. M.
Step-by-step explanation: This is because to get the area of a square you multiply base time height or b x h = x. So for this all you need to do is solve 21 x 21, which is 441 sq. M.
(P.s if you need the combined area then the answer is 882 square meters.)
Hope this helps.