Question

The radius of a sector of a circle is 7 cm. If the measure of the arc of the sector is - three right angles; find the area of the sector in case.

Answer 1

The radius of the sector of the circle, r = 7 cm

 Measure of arc of the sector = θ = 3 × 90º = 270º

∴  Area of the sector = `"θ"/360` × πr²

∴  Area of the sector =  `270/360 × 22/7 × (7)^2`  

∴  Area of the sector = `3/4 × 22 × 7`

∴  Area of the sector = `3/2 × 11 × 7`

∴  Area of the sector = `231/2`

∴  Area of the sector = 115.5 cm²