Triangles
What makes a triangle equilateral, isosceles, or scalene?
How are these triangles the same? How are they different? Manipulate the triangles by dragging their blue corner points. What happens to their side lengths?
Equilaterals have 3 equal sides. Isosceles have 2 equal sides. Scalenes do not have any equal sides.
Is the equilateral triangle still equilateral after you make it bigger or smaller? How do you know? Can you make it so that the isosceles triangle is not isosceles anymore? Why or why not? Does the scalene triangle have to stay scalene? How can you change it to make it isosceles or equilateral?
This activity supports the geometry standard 2.G.1: Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces. Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.