The angles of a quadrilateral measure 80°,100°,100°and 80° in this order. what kind of quadrilateral has this shape? how do u know

The answer is isosceles trapezoid.

If two obtuse angles are next to each other (100° and 100°) and followed by two acute angles next to each other as well ((80° and 80°), the shape is trapezoid. Trapezoid is quadrilateral shape that has a pair of parallel sides parallel. When angles on each of its base are equal, trapezoid is called isosceles trapezoid. 

This picture .