The triangles name is that because tri means three and the triangle has three sides.
a square has its name because it has four sides that makes a square.
a pentagon has 5 side thats why it has the name pentagon penta means 5.
octagon has its name because it has eight sides oct means 8 you can also think of an octopus
hexagon hex mean six so the hexagon has six sides

a square has its name because it has four sides that makes a square.

a pentagon has 5 side thats why it has the name pentagon penta means 5.

octagon has its name because it has eight sides oct means 8 you can also think of an octopus

hexagon hex mean six so the hexagon has six sides