Question

In ΔABC right angled at B, AB = 24 cm, BC = 7 m. Determine

sin A, cos A

Answer 1

Applying Pythagoras theorem for ΔABC, we obtain

AC² = AB² + BC²

= (24 cm)² + (7 cm)²

= (576 + 49) cm²

= 625 cm²

∴ AC = `sqrt(625)` cm = 25 cm

sin A  = `("Side opposite to" ∠A)/"Hypotenuse"="BC"/"AC"`

cos A = `("Side adjacent to" ∠A)/"Hypotenuse"="AB"/"AC"=24/25`