ifthyder wrote:
answer is 40. can anybody expain this.
You are basically given the diagonals of the two square. You have to find the difference of their areas.
diagonal of a square = sqrt2 * side
21 = sqrt2 * side
side = 21/sqrt2
area = 441/2
19 = sqrt2 * side
side = 19/sqrt2
area = 361/2
difference of areas = 441/2 - 361/2 = 80/2 = 40
Hope this helps.













