A triangle is a polygon. It is a closed 3-sided shape made up of straight lines. The ‘tri-’ part of the word triangle means three. A triangle has 3 sides and 3 angles. Interior angles are the angles ...

Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and develop students' reasoning with properties of different classes of triangles to ...

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 ...

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 ...