If r=10 and s=31, find r. round to the nearest tenth.

The correct answer is option c.  17.9°

Step-by-step explanation:

From the figure we can see that a right angled triangle RST.

Right angled at T

To find the value of R

It is given that,

r=10 and s=31

Tan R = Opposite side/Adjacent side

Tan R = ST/SR = r/s = 10/31 = 0.3225

R = Tan⁻¹(0.3225) = 17.87 ≈  17.9°

Therefore the correct answer is option c.  17.9°