Question

If the height of a triangle is decreased by 40% and it's base is increased by 40%, what will be the effect on its area ?​

Answer 1

Answer:

Let the original base and height of the triabgke be b units and h units respectively. Then,

Original area = 1/2bh = 0.5bh

New base = b + 40% of b = 1.4b,

New height = h – 40% of h = 0.6h

Therefore, new area = 1/2 × 1.4b × 0.6h

= 0.84bh/2

= 0.42bh

Decrease in area = 0.5 bh – 0.42bh

= 0.08bh

Therefore, percent decrease

= 0.08bh/0.5bh × 100

= 16%