Can anyone help me with this question

When turned about its axis of rotation, which shape could have created this three-dimensional object?

Arectangle has a perimeter of 20 cm. the length, x cm, of one side of this rectangle is uniformly distributed between 1 cm and 7 cm. find the probability that the length of the longer side of the rectangle is more than 6 cm long.

In the figure below, segment ac is congruent to segment ab: which statement is used to prove that angle abd is congruent to angle acd? a.)triangle acd is similar to triangle abd. b.)triangle acd is congruent to triangle abd. c.)segment a. d. is congruent to segment ac. d.)segment a. d. is congruent to segment dc.