Question

Perimeter of a rectangle is 40cm
(a)It’s longer side is x. What is it’s shorter side ?
(b)It’s area is 84 square centimeter. Find the length of it’s sides?​

Answer 1

Answer:

shorter side = 6cm

longer side = 14 cm

Step-by-step explanation:

P = 2(l+b) = 40

l+b = 20

b = 20-l

A = lb = 84

since b = 20-l

(20-l) * l = 84

20l - l^2 = 84

l^2-20l+84 = 0

L^2 - 14l - 6l +84 =0

(l-14)(l-6) = 0

so l can be either 6 or 14

if l = 14 then b =6