CC - Angle Properties of Quadrilaterals
Interior Angles Sum
The most fundamental property of any quadrilateral is that the sum of its four interior angles is always exactly 360°.
Drag the vertices of this quadrilateral along the circumscribed circle and check that the four angles always add up to 360 degrees:
Parallelogram:
- Opposite angles are equal
- Consecutive angles are supplementary (they add up to 180°)
Parallelogram
Rectangle and Square
All four interior angles are right angles (exactly 90° each).
Draw a rectangle and measure its angles to verify this property.