area of a circle free area is a designated Use this online tool to calculate the area, circumference, radius and diameter of a circle. Enter any one variable and get the other three unknowns, along with formulas and units
area of a circle Learn how to calculate the area of a circle using the formula A = πr 2 or A = πd 2 /4, where r is the radius and d is the diameter. See the derivation, examples, and real-life applications of the area of a circle
area of a triangle Learn how to find the area of a triangle using different formulas for various types of triangles, such as right, equilateral, isosceles and scalene. See solved examples and practice problems on area of triangle with 3 sides, 2 sides and angle, and Heron's formula
