What is the formula to find the circumference of a circle using the radius?

Find the value of tan theta if sin theta = 12/13 and theta is in quadrant 2

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

Jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate.true or false?