Question

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

Answer 1

Answer:

C. R = 17.9 degrees

Step-by-step explanation:

We have a rectangle triangle with the adjacent side and the opposite side (neither of which are the hypotenuse).

The relation between those elements is the tangent:

$tan(angle) = \frac{Opposite side}{Adjacent side}$

So, to isolate the angle, we modify the formula as such:

$angle = arctan(\frac{Opposite side}{Adjacent side}) = arctan(\frac{10}{31}) = arctan(0.3225) = 17.87$

If we round 17.87 degrees to the tenth... we get 17.9 degrees.

Answer 2

Answer:

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°