Can someone me with college algebra?

Prove that quadrilateral is a rhombus.

For problems 29 - 31 the graph of a quadratic function y=ax^2 + bx + c is shown. tell whether the discriminant of ax^2 + bx + c = 0 is positive, negative, or zero.

Which of the following pair(s) of circles have las a common external tangent? select all that apply. a and b a and c b and c