Question

find: sin a
right triangle with right angle, horizontal leg (opposite to angle b) labeled 21 (side a), vertical leg (opposite to angle a) labeled 28 (side b), hypotenuse labeled 35
the figure is not drawn to scale
answer
options:
\\(\frac{21}{35}\\), \\(\frac{28}{21}\\), \\(\frac{21}{28}\\), \\(\frac{28}{35}\\)

Explanation:

Step1: Recall sine definition

In a right triangle, $\sin\theta = \frac{\text{opposite}}{\text{hypotenuse}}$. For $\angle A$, opposite side is $28$, hypotenuse is $35$.

Step2: Calculate $\sin A$

$\sin A = \frac{28}{35}$

Answer:

$\frac{28}{35}$ (corresponding to the fourth option: $\frac{28}{35}$)