Quadrilaterals and Trapezoids

Quadrilaterals

Play around with the vertices of the quadrilateral. Pay attention to the angle measures in the quadrilateral.

What will the sum of interior angles in a quadrilateral always be equal to?

Consider this quadrilateral. Can you explain WHY a quadrilateral will always have an angle sum of 360 degrees?

Trapezoid

Consider the Trapezoid below. Play with the vertices.

What do you think might be some properties of a trapezoid?

Consider the Isosceles Trapezoid below.

What did you notice is different in an isosceles trapezoid than just a regular trapezoid? What generalizations can you make?