Question

the length of a rectangular blackboard is three times its width. If the width is 1.5 m. Find its area ?

Answer 1

Answer:

Given:Length=3x and Breadth=x

Width=1.5m=150cm

Perimeter=2(l+b)

⇒150=2(3x+x)

⇒150=8x

⇒x=  

8

150

​

=18.7

∴ Breadth is 18.7m and length is 3x=3×18.7=56.1m

∴Area of the black board=18.7×56.1=1,049.07‬mpower 2  

 

Cost of painting per sq.m=Rs5.50

Cost of painting 1,049.07‬mpower2  

=Rs1,049.07×5.50=Rs.5,769.885

Plz mark as brainliest

Step-by-step explanation:

Answer 2

Width of rectangle = 1.5 m

It is mentioned in the question that the length is 3 times its width

∴ length = 3 × width

              = 3 × 1.5

              = 4.5 m

We have to calculate the area

Formula to calculate the area of a rectangle:

Area = length × breadth

        = 4.5 × 1.5

        = 6.75 m²

Hence, the area of the rectangle will be 6.75 m²