Area p x r 2 in terms of radius r. The formula for the area of a circle is p x radius2 but the diameter of the circle is d 2 x r 2 so another way to write it is p x diameter 22. The formula for area A A of a circle with radius r and arc length L L is.
Now the formula for the area of the rectangle is that we know area base height Performing the corresponding substitutions for base and height respectively we will arrive at the formula for the area of the circle.
Area of a circle diameter. Hence its radius r d 2 2 2 1 cm. Arear p r. The radius is half the diameter or r d 2.