Question

Question 1 (i)
In $\Delta$ ABC, right-angled at B, AB = 24 cm and BC = 7 cm. Determine:
(i) sin A, cos A

Answer 1

In $\Delta ABC,\angle B={90}^{\circ }$

By applying Pythagoras theorem, we get:
$A{C}^2=A{B}^2+B{C}^2=(24{)}^2+7^2=(576+49)c{m}^2=625c{m}^2$
$\Rightarrow$ AC = 25
(i) $sinA=\frac{BC}{AC}=\frac{7}{25}$,
$cosA=\frac{AB}{AC}=\frac{24}{25}$