Question

Don't mind the calculations....plz answer question no:20

Answer 1

since BAC = 90° therefore BC is a semicircle ...

Area of semicircle BC = 1/2 × πr²

= 1/2 × 22/7 × (√25) × √25 {Radius by Pythagoras theorem}

= 11/7 × 25

= 275/7 cm²

Area of semicircle AB = 1/2 × πr²

= 1/2 × 22/7 × 9

= 11/7 × 9

= 99/7 cm²

Area of semicircle AC = 1/2 πr²

= 1/2 × 22/7 × 16

= 176 /7 cm²

Area of small arc AB and AC = 275 /7 - {1/2×base×height}

= 275/7 - 6

= 275 - 42 /7

= 233/7 cm²

Area of shaded region = (99+176 / 7) - 233/7

= 275/7 - 233/7

= 42/7

= 6 cm²