Trigonometry 7th Edition

$\frac{5}{4}$
Given expression- = $5 (\sin 30^{\circ})^{2}$ = 5 $(\frac{1}{2})^{2}$ [ substituting exact value of $\sin 30^{\circ}$] = $5 \times \frac{1}{4}$ = $\frac{5}{4}$