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

For example a pentagon is always a shape that has 5 sides. An equilateral triangle has 3 sides of equal length. The dashes on the lines show they are equal in length. All of the angles are also equal.

Now, more than 122 years after it was first proposed, Kamata and two other mathematicians have finally proved that a solution ...

They often identify them solely based on their resemblance to prototypes: e.g., a shape will be called a triangle if it looks like an equilateral triangle with a horizontal base – all others are ...