Question

The area of the ring between two concentric circle whose circumference are 88cm and 132cm is

Answer 1

circumference 1 = 88 cm

2πr = 88 cm

2 × 22/7 × r = 88 cm

r/7 = 2 cm

r = 14 cm

circumference 2 = 132 cm

2πR = 132 cm

2 × 22/7 × R = 132 cm

R/7 = 3 cm

R = 21 cm

the area of the ring = πR^2 - πr^2
= π (R^2 -r^2)
=22/7 (R + r)(R - r)
=22/7 (21 + 14)(21 - 14)
=22/7 × 35 × 7
=22 × 35
=770 cm^2

Answer 2

Answer:

Step-by-step explanation:

We have,

Height(h) = 24 cm and the circumferences of circular faces of a frustum = 132 cm and 88 cm.

We have,

⇒

⇒

⇒   cm

And,

⇒

⇒ cm

Slant height, l =

cm

∴  The curved surface area of the frustum

Hence, the curved surface area of the frustum 2750 .