Question

In the given ∆ABC, it is given that ∠B = 90°, AB = 24 cm and BC = 7 cm. Then, cos A = ?
Figure

(a) $\frac{7}{24}$
(b) $\frac{7}{25}$
(c) $\frac{24}{25}$
(d) None of thse

Answer 1

(c) $\frac{24}{25}$


Here, AB = 24 cm and BC = 7 cm
Now, using Pythagoras theorem, we get:
AC² = AB² + BC²
⇒ AC² = (24)² + (7)²
⇒ AC² = 625
⇒ AC = 25 cm
∴ cos A = $\frac{AB}{AC}=\frac{24}{25}$