Question

If the length of a rectangle is 15cm more than it's width and the perimeter is 150cm find the dimensions of the rectangle . Factorise qus

Answer 1

Given that,

the length of a rectangle is 15cm more than it's breadth.

let the breadth of the rectangle be x.

therefore it's length = x + 15

perimeter of the rectangle is given = 150cm

formula to find the perimeter of a rectangle is 2(l + b)

so we can write,

➡2(l + b) = 150cm

➡ 2(x + 15 + x) = 150cm

➡ x + 15 + x = 150/2

➡ 2x + 15 = 75cm

➡ 2x = 75 - 15

➡ x = 60/2

➡ x = 30cm

hence the dimensions of the rectangle are :-

• breadth = x = 30cm

• length = x + 15 = 45cm

VERIFICATION :-

perimeter = 2(l + b)

= 2(45 + 30)

= 2 × 75

= 150cm

hence verified!

Answer 2

Length of rectangle is equal to 15 + b  

Breadth of rectangle is equal to b  

Perimeter is equal to 150

Equation

Perimeter is equal to 2 l + b  

2 l + b is equal to p

 2 into l + 15 + b is equal to 150  

2b+ 30 + 2B is equal to 150

4B is equal to 150 - 30

4B is equal to 120  

b is equal to 120 divided by 4

b is equal to 30

Therefore;

breadth is equal to b is equal to 30

length is equal to b + 15 is equal to 30 + 15 is equal to 45