Question

The sides of a triangle are 10 cm, 10 cm and 12
cm. If each of the two equal sides is increased
in the ratio 5 : 4, but the third side remains
unchanged in what ratio has its perimeter been
increased ?

Answer 1

ANSWER

Given, sides of the triangle =10cm,10cm,12cm

∴ perimeter of the given triangle =10+10+12=32cm

As the two equal sides each 10cm increased in the ratio 5:4

So, the corresponding sides of the new triangle=10×

4

5

=12.5cm

Hence the 3 sides of the new triangles are 12.5cm,12.5cm,12cm.

Then the perimeter of the new triangle =12.5+12.5+12=37cm

∴The ratio in which the perimeter of the new triangle is increased

=

perimeter ofgiven triangle

perimeter of the new triangle

=

32

37

Hence the ratio =37:32