Question

Find the area of the above triangle if it is given that $\sin x=0.8$.

• A. $0.48$
• B. $4.8$
• C. $24$
• D. $48$

Answer 1

The correct option is C $24$

Since the triangle shown is a right angled triangle, its area would be given by $\frac{1}{2}\times$ base $\times$ height $=\frac{1}{2}\times$ sides containing the right angle.

Those sides are $10\cos x$ and $10\sin x$ respectively.

$\therefore$ area $=10\cos x\times 10\sin x\times \frac{1}{2}$

$=\frac{1}{2}\times 10\times 0.8\times 10\times \sqrt{1-(0.8{)}^2}$

$=\frac{1}{2}\times 10\times 0.8\times 10\times 0.6$

$=24$