Question

find: cos a
the figure is not drawn to scale.
triangle with right angle, side adjacent to angle a is 30, side opposite to angle a is 40, hypotenuse is 50
options: 40/50, 30/40, 40/30, 30/50

Explanation:

Step1: Recall cosine definition

In a right triangle, $\cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}}$ for an acute angle $\theta$.

Step2: Identify sides for angle A

For angle A, adjacent side is 30, hypotenuse is 50.

Step3: Calculate $\cos(A)$

$\cos(A) = \frac{30}{50}$ (simplifies to $\frac{3}{5}$, but option is $\frac{30}{50}$).

Answer:

$\frac{30}{50}$ (matching the option with 30/50)