Question

An umbrella has $8$ ribs which are qually spaced.Assuming the umbrella to be a flat circle of radius $56$cm. Find the area between the two consecutive ribs.

Answer 1

REF.Image

Area of rib = $\frac{1}{8}\times$ Area of umbrella

Radius r= 56 cm

Area of umbrella = Area of circle

$=\pi r^2$

$=\frac{22}{7}\times 56\times 56$

$=\frac{22}{7}\times 3136.$

Area of rib = $\frac{1}{8}\times$ area of umbrellas

$=\frac{1}{8}\times \frac{22}{7}\times 3136$

$=\frac{11\times 3136}{4\times 7}c{m}^2=\frac{34.496}{4\times 7}c{m}^2$

Hence, Area between two consecutive ribs are

$\frac{34,496}{4\times 7}c{m}^2$