Understanding different types of angles and that angles in a triangle sum to 180° can be helpful when classifying a triangle. Recognising line symmetry and rotational symmetry will also help. Look for ...

Named for Plato, who theorized that the classical elements were made of these regular polyhedrons, three of the Platonic solids are composed of equilateral triangles: the tetrahedron, octahedron, and ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. They all have straight rays or sides if they're part of a shape and a vertex, that's the point where ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. What is a quadrilateral? A quadrilateral is a four-sided shape where each of the sides are straight and ...

The sum of interior angles in a quadrilateral is 360°. This fact is a more specific example of the equation for calculating the sum of the interior angles of a polygon: \(\text {Sum of interior angles ...