Question

find the diameter of each whose area is 38.5cm2​

Answer 1

22÷7×r×r=38.5

then r×r= 38.5×7÷22

=12.25

• r=3.5
• d=r×2=3.5×2=7
• so the diameter is 7cm

Answer 2

Step-by-step explanation:

area of a circle =πr^2

=> 38.5=22/7×r^2

=>38.5×7/22=r^2

=>3.5×(7/2)=r^2

=>(35/10)×(7/2)=r^2

=>(7×5×7)/(10×2)=r^2

=>7×7/2×2=r^2

=>7/2cm=r^2

since, diameter= 2r

hence d=2×7/2=7cm