Question

In given figure, the radius at the circle with centre 0 is 7 cm, ZPOQ = 60°, angleAOB = 40° and2angleCOD = 80°. Find the area of the shaded region [CBSE 2011 C]​

Answer 1

Answer:

answer : 77cm²

area of shaded region = $\frac{80^{\circ}}{360^{\circ}}\times\pi r^2+\frac{60^{\circ}}{360^{\circ}}\times\pi r^2+\frac{40^{\circ}}{360^{\circ}}\times\pi r^2$

= $\frac{80^{\circ}+60^{\circ}+40^{\circ}}{360^{\circ}}\times\pi r^2$

= $\frac{180^{\circ}}{360^{\circ}}\times\pi r^2$

= $\frac{1}{2}\times\pi r^2$

here, r = 7cm

so, area of shaded region = 1/2 × 22/7 × 7 × 7 cm²

= 11 × 7 cm² = 77cm²

hence, area of shaded region is 77cm²

Answer 2

Answer:

answer : 77cm²

area of shaded region = \frac{80^{\circ}}{360^{\circ}}\times\pi r^2+\frac{60^{\circ}}{360^{\circ}}\times\pi r^2+\frac{40^{\circ}}{360^{\circ}}\times\pi r^2

= \frac{80^{\circ}+60^{\circ}+40^{\circ}}{360^{\circ}}\times\pi r^2

= \frac{180^{\circ}}{360^{\circ}}\times\pi r^2

= \frac{1}{2}\times\pi r^2

here, r = 7cm

so, area of shaded region = 1/2 × 22/7 × 7 × 7 cm²

= 11 × 7 cm² = 77cm²

hence, area of shaded region is 77cm²