Pleaseee helllp!

Which of the following statements is not true? a. parallel lines are lines in the same plane that never intersect. b. congruent figures have the same shape and same size angles and sides. c. similar figures must have the same shape and the same size. d. a rotation is when you turn a figure around a certain point.

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)