In an isosceles trapezoid, which of the following is true?
A.All sides are equal
B.The diagonals are unequal
C.The non-parallel sides are equal
D.Opposite angles are equal
Answer: C
An isosceles trapezoid is a quadrilateral with a pair of parallel sides and a pair of equal non-parallel sides. Its diagonals are also equal in length, and base angles are equal.