# How many isosceles trapeziums?

In Mathematics, an isosceles trapezium is a quadrilateral one pair of opposite sides are parallel and the base angles are equal in measure. Alternative definitions are a quadrilateral with an axis of symmetry bisecting one pair of opposite sides, or a trapezoid with diagonals of equal length.

How many isosceles trapeziums do you count in this figure?

Just for the sake of clarity, three triangles in one row would make an isosceles trapezium, as the red one in this example:

You can check your solution at here

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