Question

find the diameter of a circle whose circumference is equal to the sum of circumferences of circles with radii 10 cm , 12cm , 18cm

Answer 1

62.83+75.39+113.09=251.31
the circumference is 251.31
by the formula 2πr
r is 39.99
d=2r
79.98
answers is 79.98cm

Answer 2

Answer:

Step-by-step explanation:

Given :-

Radii of the circumferences = 10 + 12 + 18 = 40 cm

To Find :-

Diameter of a circle

Solution :-

Let the radius of the circle = R cm

2πR = 2π × 10 + 2π × 12 + 2π × 18

On dividing each term by 2π, we get:

R = 10 + 12 + 18 = 40 cm

Radius of the circle obtained = 40 cm

And, its diameter = 2 × Radius

Diameter  = 2 × 40 cm = 80 cm

Hence, the Diameter of a circle is 80 cm.