Every rule the plots and drills lean on. One board, no guessing.
| Angle sum of a triangle | The three angles always total 180°. |
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| Vertical angles | Across the X of two crossing lines, the angles are equal. |
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| Parallel lines and a transversal | Alternate interior angles come out equal. |
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| Pythagorean theorem | a2 + b2 = c2 in every right triangle. |
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| Congruence tests | SSS, SAS, ASA. Match the parts in order and the triangles match whole. |
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| Similar triangles | Equal angles, and every pair of matching sides in the same proportion. |
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| Triangle area | Half of base · height. |
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| Parallelogram area | Base · height. |
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| Trapezoid area | Average the two parallel sides, then multiply by the height. |
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| Circumference | C = 2πr, all the way around the circle. |
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| Circle area | A = πr2. |
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| Inscribed angle | An inscribed angle is half the central angle on the same arc. |
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| Prism and cylinder volume | Base area · height. |
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| Pyramid and cone volume | One third of base area · height. |
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| Distance and midpoint | Right-triangle the two points for distance; average the coordinates for the middle. |
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