Quarter Circle Area Calculator A = πr²/4. Radius Area 19.635 Step-by-step with your numbers: 1. Values used: 2. Radius = 5 3. Area = 19.635 Did we solve your problem today? 👍 Yes 👎 No Thanks for the feedback! Quarter circle area. FAQ Perimeter? P = πr/2 + 2r. Related calculators Circle Calculator Find a circle's area, circumference and diameter from its radius. Semicircle Area Calculator Area and perimeter of a semicircle. Sector Area Calculator Find the area and arc length of a circle sector.