How can i make a recursive formula to calculate the factorial of number?

Match the term on the left with its image or description on the right. match term definition diameter a) circle a and a line segment connecting points b and c which are on the circle. circumference b) circle a and a line segment connecting points b and c which are on the circle. radius c) a piece of the circumference of a circle secant d) two circles that share the same center. concentric circles e) the distance around a circle arc f) a segment between two points on a circle that passes through its center

Can someone me with my hwplz(only the circled ones)

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.