3. what's the measure of an arc with a central angle of 90 °?

The measure of an arc is equal to the measure of an arc's central angle.

So the measure of an arc with a central angle of 90 ° is also 90 °.

answer:

because the gravitational attraction of our sun for the earth is the centripetal force causing the earth's circular motion around the sun, we can use netwon's law of universal gravitation to find the mass of the sun without ever actually visiting the sun. this is the same technique you would use to determine the mass of cygnus x-1 with a probe. the earth, orbiting the sun, plays the same role as the probe sent to orbit cygnus x-1.

f(force of gravity) = f(centripetal force)

explanation:

answer: who is joe?

explanation: