A circular flower bed is 21 m in diameter and has a circular sidewalk around it that is 4 m wide. Find the area of the sidewalk in square meters.

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota

Jane’s favorite fruit punch consists of pear, pineapple, and plum juices in the ratio 5: 2: 3. how many cups of pear juice should she use to make 20 cups of punch?

Peter measures the angles in a triangle. he finds that the angles are 95, 10 and 75. is he correct? explain your answer