Question

The diameter of two circles are 36 cm and 20 cm respective -- Piese area of the c
which has circumference equal to the sum of the circunferences of the two circles.
find ratio of area of this big circle and the sum of area of two s nalí eszcie.
10​

Answer 1

HI FRIEND

GOOD QUESTION

Answer. cm=10 cm. =(36+20)π cm=56π cm. This is the circumference C of the resulting circle

Answer 2

Area = 2464 cm²

Ratio = 98 : 53

Let the radius of the required circle be 'R'.

Radius of 1st circle = d/2 = 36/2 = 18 cm

Radius of 2nd circle = 20/2 = 10 cm

As given, circumference of biggest circle = circumference of 1st circle + circumference of 2nd circle.

=> 2π(18) + 2π(10) = 2πR

=> 2π[18 + 10] = 2πR

=> 18 + 10 = R

=> 28 = R

Area of biggest circle= πR² = π(28)² = π(784) = 2464 cm²

Sum of area of 1st + 2nd circle = π(18)² + π(10)² = π(18² + 10²) = π(424)

Required ratio = π(784)/ π(424)

Required ratio = 784/424 = 98/53