Question

The radius of two circles are 19 cm and 9 cm respectively.Find the radius of the circle which has circumference equal to the sum of the circumferences of the two circles

Answer 1

r=19
circumference=2 x 22/7 x 19
=44/7 x 19 = 836/7
r= 9
circumference=2 x 22/7 x 9
=44/7 x 9 = 396/7
sum of circumferences = 836/7 +396/7
= 1232/7
1232/7 = 2 x 22/7 x r
1232 = 44r
1232/44 = r
28 = r

Answer 2

Answer ✅✅✅

radius of first circle = 19 CM

circumference of first circle = 2πr1

radius of second circle = 9cm

circumference of second circle =2πr2

now

circumference of both circle=2πr1+2πr2

= 2π(r1+r2)

=2 ×22/7 (19+9)

=2×22/7 (28)

= 2×22×4

= 176cm

Since circumference of both circle = circumference of bigger circle

2πr = 176cm

2×22/7×r = 176cm

44/7 r =176

r= 176 × 7

—

44

r= 28 cm

Hence the radius of bigger circle= 28cm.