For a printable version, click here . A quadrilateral having two and only two parallel sides.
Isosceles trapezoid A trapezoid whose legs are congruent.
The base angles of an isosceles trapezoid are congruent. If the base angles of a trapezoid are congruent, the trapezoid is isosceles. The opposite sides of a parallelogram are parallel. A diagonal of a parallelogram divides it into two congruent triangles. The opposite sides of a parallelogram are congruent.