Question

If HJR is 9/10 π, what is RHJ?

Answer 1

Answer:

A.

Step-by-step explanation:

We know that the whole length of the circumference is $2 \pi$.

By given, we have $HJR=\frac{9}{10} \pi$, and $HJ=81\°$ by definition of central angle.

That means

$HJR=HJ+RJ\\\frac{9}{10} \pi = 81\° +RJ\\ 162\°-81\°=RJ\\RJ=81\°$

Also,

$RHJ=360\° - RJ=360\° - 81\° =279\°$

Therefore, the measure of the arc RHJ is 279° which is equivalen to choice A.

$\frac{31}{20}\pi = \frac{31}{20} \times 180\° = 279\°$