Interior angles in a triangle add up to 180˚. Triangles close triangleA polygon with three straight sides. have three sides, therefore they have three angles. Interior angles in a triangle sum to a ...

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 ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. What is a triangle? We all know that a triangle is a three-sided shape — 1, 2, 3 sides. A triangle also ...

Parallel lines close parallel lines Lines which never meet and stay the same distance apart. Parallel lines are indicated by a pair of arrows. are two or more straight lines that remain the same ...