Area and circumference of a circle Quiz Welcome to your Area and circumference of a circle Quiz Please click "Next" Calculate the area of a circle Use formula: A = πr². Round the answer to the nearest tenths of a centimeterA = cm² Determine the area of a circle Use formula: A = πr². Round the answer to the nearest tenths of a centimeterA = cm² What is the circumference of a watermelon Use formula: C = πd. Round the answer to the nearest tenths of a centimeterC = cm Determine the circumference Use formula: C = 2πr. Round the answer to the nearest tenths of a centimeterC = m Determine the area of a semi circle Use formula: A = ½πr². Round the answer to the nearest tenths of a centimeterA = cm² Time's upTime is Up!