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 ...

Two-dimensional (2D) shapes are completely flat. They have two dimensions – length and width. A polygon is a closed 2D shape with straight sides that meet at vertices. Polygons can be regular or ...

A scalene triangle has 3 sides of different lengths and 3 unequal angles. An isosceles triangle has 2 sides of equal length. (The dashes on the lines show which are equal in length.) The angles at the ...