Question

In a $\Delta ABC$, $\angle B={90}^o,AB=24cm$ and $BC=7cm$.

Find (i) sin A (ii) cos A (iii) sin C (iv) cos C.

Answer 1

In Δ ABC, right-angled at B ,using Pythagoras theorem we have

AC² = AB² +BC² = 576 + 49 = 625
Or AC=25 ( taking positive value only)
Now

(i) In a right angle triangle ABC where B=90° ,
(i) Sin A = BC/AC = 7/25

(ii) CosA = AB/AC = 24/25

(iii) Sin C = AB/AC = 24/25

(iv) Cos C = BC/AC =7/25