Question

The radii of two circles are 19 cm and 9cmrespectively.find the radius of the circle which has circumference equal to the sum of the circumference of the two circles.

Answer 1

answer is 28 when you let first circle radius r1 and second circle radius r2 and resulting circle radius R.by adding 2py cancel by both sides then result is 28

Answer 2

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.

hope it helps u