2D shapes are flat, plane shapes. Triangles have three sides and three angles that add up to 180°. Quadrilaterals have four sides and four angles that add up to 360°. Constructing triangles Learn how ...

A triangle is a 2D shape with three sides and three angles. The angles in a triangle add up to 180°. The properties of different kinds of triangles are listed below.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Some examples of solids that incorporate 2D shapes are mentioned in this video by Sanchit — for example ...