Someone please help

If the measure of xyz is 81 what is the measure of yz

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

Acircle has a circumference of 2 pi cm. which statement about the circumference and area is true? a comparison of the area and circumference is not possible since the area cannot be determined. the numerical values of the circumference and area of the circle are equal. the numerical value of the circumference is greater than the numerical value of the area. the numerical value of the circumference is less than the numerical value of the area.