Question

1. The length and breadth of a rectangle are (3a-4b)cms and (5b+2a)cms. find it area and perimeter. ​

Answer 1

Answer:

Step-by-step explanation:

Perimeter=2(l+b)

=2(3a-4b+5a+2a)

=2(10a-4b)=20a-8b.

Area=l×b

=(3a-4b)×(7a)

=21a^2-28ab.

Answer 2

Area = 6a² + 13ab - 5b² cm²

Perimeter = 10a + 2b cm

Step-by-step explanation:

Given, the length of the rectangle = 3a - 4b cm

and width = 5b + 2a cm

So, perimeter

= 2 (length + breadth)

= 2 × (3a - 4b + 5b + 2a) cm

= 2 × (5a + b) cm

= 10a + 2b cm

So, area

= length × breadth

= (3a - 4b) (5b + 2a) cm²

= 15ab + 6a² - 5b² - 2ab cm²

= 6a² + 13ab - 5b² cm²

SPJ3