Answer:
b. x = 123
Step-by-step explanation:
The number is 8 because
And if you add 4, you get 20
Hence, the number is 8
314.16 sq mm
formula for area of a circle = pi(r^2)
if the diameter is 20mm then the radius is 10 mm
When you plug in pi(10mm^2) you get 314.16 sq mm
