Double Math

• A quadrilateral (in geometry) can be defined as a closed,  two-dimensional shape which has four straight sides(edges).
• The polygon which has four vertices or corners.
• Interior angles equal to 360^\circ[\katex]
• A quadrilateral can be regular or irregular

We can find the shape of quadrilaterals in various things around us, for example in a chessboard, a deck of cards, a kite, a tub of popcorn, a signboard, and an arrow.

There are many types of quadrilateral (in geometry). As the word, ‘Quad’ means 4 all these types of a quadrilateral have four sides, and the sum of angles of these shapes is 360 degrees.

• Trapezium
• Parallelogram
• Squares
• Rectangle
• Rhombus
• Kite

Trapezium actually Describing a geometric shape, has two contradictory meanings:

Outside the US and Canada: A quadrilateral with at least one pair of parallel sides (known in the US as a trapezoid)

In the US and Canada: A quadrilateral with no parallel sides (known elsewhere as a general irregular quadrilateral)

Trapezium can also mean:

• Trapezium (bone), a bone in the wrist
• Trapezium (astronomy), a group of stars in the Orion Nebula