Isosceles trapezium (British isles) or isosceles trapezoid (US): a person set of reverse sides are parallel and the base angles are equal in measure. Alternative definitions are a quadrilateral having an axis of symmetry bisecting a person set of reverse sides, or possibly a trapezoid with diagonals of equal length. https://andreirxch.humor-blog.com/26776731/everything-about-types-of-quadrilaterals