Question

Find the perimeter of the following:

A triangle of sides measuring $21\mathrm{cm},17\mathrm{cm}$and $11\mathrm{cm}$.

Answer 1

We know that, the perimeter of a closed figure is the length of its boundary.

Since, a triangle has three sides,

Thus, perimeter of triangle $=$Sum of length of all three sides

$\Rightarrow$Perimeter of given triangle$=(21+17+11)\mathrm{cm}$

$=49\mathrm{cm}$

Hence, the perimeter of given triangle is $49\mathrm{cm}$.