Question

what are the exact values of a and b?
o a = 7/2, b = 7√3
o a = 7/2, b = 7√2/2
o a = 7√3/2, b = 7/2
o a = 7/2, b = 7√3/2

Explanation:

Step1: Use sine function for a

$\sin(30^{\circ})=\frac{a}{7}$, so $a = 7\times\sin(30^{\circ})=\frac{7}{2}$

Step2: Use cosine function for b

$\cos(30^{\circ})=\frac{b}{7}$, so $b = 7\times\cos(30^{\circ})=\frac{7\sqrt{3}}{2}$

Answer:

$a=\frac{7}{2},b = \frac{7\sqrt{3}}{2}$