What is the volume of a cone with a radius of 4 cm and a height of 5 cm help

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

Plz hurry evaluate the expression a+b where a=8 and b=19

Aladder that is 20ft long is leaning against the side of a building. if the angle formed between the ladder and the ground is 75 degrees how far is the bottom of the from the base of the building?