Practice the Pythagorean theorem: a² + b² = c². Find missing sides of right triangles and distances between points.
In a right triangle, a² + b² = c², where a and b are the legs and c is the hypotenuse (the longest side). If the legs are 3 and 4, then c = √(9 + 16) = √25 = 5.
Square both legs, add them, and take the square root: c = √(a² + b²).
Cubles kits are geometry in your hands: nets, faces, edges and vertices that fold and click into a poseable 3D character. No scissors, no glue, about 15 minutes.
