Explain how to calculate the circumference of a circle when given either a diameter or radius and also how to estimate the circumference of a circle for a multiple choice question. please help me

20 points! asap! a is known to be 6,500 feet above sea level; ab = 600 feet. the angle at a looking up at p is 20°. the angle at b looking up at p is 35°. how far above sea level is the peak p? find the height of the mountain peak to the nearest foot. height above sea level =

What value of x will make the triangles similar by the sss similarity theorem?

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.