Question

The breadth of rectangle is $\frac{4}{5}$ of the radius of the circle.The radius of the circle is $\frac{1}{5}$ of the side of a square,whose area is $625cm^2$ . What is the area of the rectangle if the length of rectangle is 20cm?

• A. 80 cm
• B. 45 cm
• C. 50 cm
• D. 78 cm

Answer 1

Answer:

A. 80 cm

breadth of rectangle is $\frac{4}{5}$ of the radius of the circle.

$B=\frac{4}{5}r$

radius of the circle is $\frac{1}{5}$ of the side of a square

$r=\frac{1}{5}a$

Area of Square $a^2=625cm^2$

rectangle if the length of rectangle is 20cm

$L=20cm$

$a^2=625$

$a=25cm$

$r=\frac{1}{5}\times{25}$

$r=5cm$

$B=\frac{4}{5}\times{5}$

$B=4cm$

Area of Rectangle $=L\times{B}$

$=20\times{4}=80cm^2$