43. 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
Answers
Answer:
Area = π(784) = 2464 cm²
Ratio = 98 : 53
Step-by-step explanation:
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
Diameter = 36 cm and 20 cm
Ratio of area
At first
Radius = 36/2
Radius = 18 cm
Radius = 20/2
Radius = 10 cm
Now
Circumference = 2πr
2πr + 2πr' = 2πR
2π(r + r') = 2πR
2π(18 + 10) = 2πR
2π(28) = 2πR
28 = R
So
Radius = 28 cm
Area = πr²
Area = 22/7 × 28 × 28
Area = 352 cm²
Now
Sum of Areas = π(18² + 10²)
Sum of Areas = π(324 + 100)
Sum of Areas = π(424)
Now
Ratio = π784/π424
Ratio = 784/424
Ratio = 98/53