geometry

  • Complementary Angles: add to 90°.

  • Supplementary Angles: add to 180°.

  • Vertically Opposite Angles: equal

  • Angle Sum of a triangle: add to 180

  • Equilateral Triangle: every angel = 60

  • Isosceles Triangle: base angels are equal

  • Exterior Angle of a Triangle: the exteriror angel equals the sum of the two interior remote angles