How to Calculate Arc Area
- 1). Notice the angle formed by the two radii. Divide this angle by 360 to find out what portion of the circle it represents. For instance, if the angle is 45 degrees, divide 45 by 360 to get 0.125.
- 2). Find the area of the circle by squaring the radius and multiplying that by 3.14 (pi). For example, if the radius is 10 cm, square 10 to get 100. Then multiply 100 times 3.14 to get a circle area of 314 square cm.
- 3). Multiply your answer from Step 1 by your answer from Step 2 to find the area of the arc's sector. Therefore, 0.125 times 314 equals 39.25. The area of the arc's sector is 39.25 square cm.