Question

A path of uniform width 3m runs around the outside of a square field of side 21 m find the area of the path

Answer 1

ar of path = ar of (4 rectangle + 4 square) 
                = 4 ( l X b + s X s )
                 = 4 ( 21 X 3 + 3 X 3 )
                 = 4 ( 63 + 9 )
                 = 4 X 72
                 = 288 cm sq.

Answer 2

21×21=421
24×24=576
576_421=155meter squire