Question

if the height of a triangle is decreased by 40%and its base is increased by 40% ,what will be the percentage in its area?

Answer 1

If a certain number changes successively by A% and B%, the effective percentage change = A+B+AB/100

In this case, Effective percentage change = 40−40+(40∗−40)/100

= -16 %

Hence the Area of the new triangle decreases by 16%.

Answer 2

Here is your solution.