Drag triangles into place to make patterns. You can rotate a triangle by 180 degrees by clicking on it.
Can you make a pattern that has parallel lines in it?
Can you make a pattern that has vertical angles in it?
Can you show that the internal angles of the triangle add up to 180 degrees?
Can you make a similar triangle with sides that are twice as long as the sides of the tiling triangle? Is it twice as big?