Can someone please help me with math. Please don't put any links thank you!

Determine whether the following statements are true and give an explanation or counterexample. bold a. when using the shell method, the axis of the cylindrical shells is parallel to the axis of revolution. bold b. if a region is revolved about the y-axis, then the shell method must be used. bold c. if a region is revolved about the x-axis, then in principle it is possible to use the disk/washer method and integrate with respect to x or the shell method and integrate with respect to y.

How do i find the missing angle measure in a polygon

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?