Answer : AREA OF A CIRCLE = PIR2 ( PI ×R ×R )
N.B = R MEANS RADIUS.
GIVEN THE CIRCUMFERENCE, WE WILL USE THE CIRCUMFERENCE TO FIND THE RADIUS.
FORMULA FOR FINDING RADIUS = CIRCUMFERENCE ÷ 2 × 3.142.
SO THAT IS : 31.4 ÷ 6.284 = 4.9.
ROUND UP : 5.
SO THE RADIUS IS 5. NOW WE CAN FINDING THE AREA. 3.14×5×5 = 78.5 . Say thanks Nique.