Question

if the radius of circle is deminished by10% then the area of cirlce is deminished is ?​

Answer 1

Let, the radius be r. Then area of circle = PI × r × r

Radius is diminished by 10% so New radius, R = r - ( 10 × r / 100 )

= > R = 0.9 × r

New area = PI × R × R

Putting value R = 0.9 × r

New area = 0.81 × PI × r × r

Difference = Old area - New area

=> Difference = PI × r × r - 0.81 × PI × r × r

=> Difference = 0.19 × PI × r × r

Diminished area = 19%