Answer:
Option A is correct
30°
Step-by-step explanation:
Using sine ratio:
[tex]\sin \theta = \frac{\text{Opposite side}}{\text{Hypotenuse side}}[/tex]
In a given triangle ACB:
BC = 9 units and AB = 18
Opposite side of angle A = BC = 9 units
Hypotenuse side = AB = 18 units.
By sine ratio:
[tex]\sin A = \frac{9}{18}[/tex]
[tex]\sin A = \frac{1}{2}[/tex]
[tex]\sin A = \sin 30^{\circ}[/tex]
On comparing both sides we have;
[tex]\angle A = 30^{\circ}[/tex]
therefore, the measure of angle A is 30 degree.
