# Area Of Circle With Diameter

Area Of Circle With Diameter. Circumference of a circle = 2πr, where. R = radius of the circle. Therefore, circumference of a circle = 2πr = 50. ⇒ πr = 25.

Area of a circle with diameter. We know that the diameter of a circle equals twice the radius of the circle, numerically. $$(d = 2r)$$ area $$\pi \times {\left( {\frac{d}{2}} \right)^2} = \frac{{\pi {d^2}}}{4}$$, where $$d$$ represents the diameter of the circle. Derivation of the formula for area of a circle Given the radius of a circle, find its area. For example, if the radius is 5 inches, then using the first area formula calculate π x 5 2 = 3. 14159 x 25 = 78. 54 sq in. Find the area of a circle given its diameter is 12 cm. Apply the second equation to get π x (12 / 2) 2 = 3. 14159 x 36 = 113. 1 cm 2 (square centimeters). Calculate the area, circumference, radius and diameter of circles.