Question

What will be the length of a rectangle of breadth 10 cm whose perimeter is 42 m?

Answer 1

Explicação passo a passo:

A rectangle has two pairs of equal sides. (See the image).

The length is $L$.

We know that the perimeter is $P=42$ m $=4200$ cm. So, we have

$10+10+L+L=4200\\\\20+2L=4200\\\\2L=4200 - 20=4180\\\\L=\dfrac{4180}{2}\\\\L=2090$ cm

Remember that $1$ m $=100$ cm. So, $42$ m $=42\cdot 100=4200$ cm.