If the sum of the two diameters is 200 mm, find the radius of the circle in cm.

In a circle, the sum of two diameters = 200 mm

Let diameter be d and radius be r of a circle.

⇒ d + d = 200 mm

⇒ 2d = 200 mm

∴ d = 100 mm

We know that Diameter = 2(Radius).

⇒ 100 = 2r

⇒ r = 100 ÷ 2

∴ r = 50 mm

We know that 1 cm = 10 mm.

⇒ r = 50 ÷ 10 = 5 cm

∴ The radius of the circle is 5 cm.