Given: Circumference of circle = 176 cm Concepts used: Circumference of circle = 2 × π × radius of the circle The diameter of circle = 2 × radius of the circle Calculation: Let the radius of the circle be r cm. Circumference of circle = 2 × π × radius of circle ⇒176cm=2×π×r ⇒176cm=2×22/7×r ⇒176cm=44/7×r ⇒(176×7)/44=r ⇒ r = 28 cm Diameter of circle = 2 × r ⇒2×28cm ⇒56cm . ∴ The diameter of the circle is 56 cm.