The question is missing parts. Here is the complete question.
Quadrilateral PQRS (shown below) is an isosceles trapezoid. If RP = 12, then SQ = ?
Answer: SQ = 12
Explanation: A trapezoid is a quadrilateral with two opposite parallel sides, called bases. The trapezoid is an isosceles trapezoid when the non-parallel sides have the same length.
One property of isosceles trapezoid is that its diagonals are congruent, i.e., have the same length.
In the picture, segment RP is one of the trapezoid's diagonal. It is asking the measure of SQ, which is the other diagonal. So:
SQ = RP
SQ = 12
Segment SQ of isosceles trapezoid PQRS is 12 units.