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Question
What is the diameter of a circle whose area is equal to the sum of the areas of two circles of radii 40cm and 9cm?
Solution
Area of the circle = sum of areas of 2 circles
πR2 = π(40)2 + π(9)2
πR2 = π × (402 + 9)2
R2 = 1600 + 81
R2 = 1681
R = 41 cm.
Diameter of required circle = 41 × 2 = 82 cm
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