Question

Height of a triangle is decreased by 25% and its base increase by 50% its area will be

Answer 1

hope it helps..........

Answer 2

Given,

The height of a triangle is decreased by 25% and its base increase by 50%.

To Find,

The area of a triangle.

Solution,

Let the original height and base be h and b respectively and a = area of a triangle originally.

Now,

Final height

$= \: h - \frac{25}{100} \times h$

$= \frac{75}{100} \times h$

$= \frac{3}{4} h$

Final base length

$= b + \frac{50}{100} b$

$= \frac{3}{2} b$

The original area of a triangle

$= \frac{1}{2} \times b \times h$

$= a$

The final area of a triangle

$= \frac{1}{2} \times \frac{3}{4} \times h \times \frac{3}{2} \times b$

$= \frac{1}{2} \times \frac{9}{8} \times h \times b$

$= \frac{9}{8} \times original \: area$

$= \frac{9}{8} a$

The final area is more than the original, area.

So, the percentage increase in area is

$(\frac{9}{8} a - a ) \times 100= \frac{1}{8} a \times 100$

=12.5

Henceforth, the percentage increase in area is 12.5%.