Quadrilaterals

A quadrilateral is a polygon with four sides. Its family includes the rectangle (four right angles), the square (four right angles and four equal sides), the parallelogram (two pairs of parallel sides), the rhombus (four equal sides), the trapezium (one pair of parallel sides) and the kite (two pairs of equal sides next to each other). A square is a rectangle and a rhombus at once. A diagonal joins two opposite vertices and cuts a quadrilateral into two triangles, so its angles add up to 360°.

Watch · Depth 1 · 90 sA family of four sidesSix four-sided shapes, each named by its rule - and why a square is a rectangle and a rhombus at once. Plus the 360 degrees inside every one.