Question

What is the measure of angel A rounded to nearest whole number ?

A. 30 degrees
B. 28 degrees
C. 2 degrees
D. 62 degrees

Answer 1

Use inverse cosine here because you have the side adjacent to angle A and the hypotenuse.  On your calculator, press the 2nd key then cosine to see this on your display $cos^{-1}$ then enter 8/17 to give you an angle measure of 62 degrees.

Answer 2

Answer:

D. 62 degrees

Step-by-step explanation:

Here, ABC is a right angles triangle,

In which,

AB = 8 units,

AC = 17 units,

∠B = 90°,

By the pythogorous theorem,

$AC^2=AB^2+BC^2$

$17^2=8^2+BC^2$

$289=64-BC^2$

$225=BC^2$

$\implies BC=15\text{ unit}$

By the law of sine,

$\frac{sin A}{BC}=\frac{sin B}{AC}$

$\frac{sin A}{15}=\frac{sin 90^{\circ}}{17}$

$sin A = \frac{15}{17}$

$\implies A= 61.9275^{\circ}\approx 62^{\circ}$

Hence, the measure of angle A is 62 degrees,

Option D is correct.