Question

If the perimeter is $40\text{cm}$, make an equation, and find $x$.

Answer 1

If $L$ and $B$ are the lengths and breadths of a rectangle then the perimeter of rectangle is given by;

$P=2(L+B)$

According to the given condition:

$L=(x-5)\text{cm}$

$B=8\text{cm}$

$P=40\text{cm}$

$2(x-5+8)\text{cm}=40\text{cm}$

$x+3=20$

$x=17\text{cm}$ Ans.