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Mathematics
Geometry
Term | Definition |
---|---|
Addition Property of Equality | If a = b, then a + c = b + c |
Subtraction Property of Equality | If a = b, then a - c = b - c |
Division Property of Equality | If a = b, then ac = bc |
Reflexive Property of Equality | a = a |
Symmetric Property of Equality | If a = b, then b = a |
Transitive Property of Equality | If a = b, then b can be substituted for a in any expression. |
Distributive Property of Equality | a( b + c ) = ab + ac |
Reflexive Property of Congruence | Figure a ≅ Figure a |
Transitive Property of Congruence | If figure a ≅ figure b ≅ figure c, then figure a ≅ figure c |
Symmetric Property of Congruence | If figure a ≅ figure b, then figure b ≅ figure a |
Parallel lines | Are coplanar and do not intersect. |
Perpendicular lines | Intersect at a 90° angle. |
Skew lines | Not coplanar and not parallel, do not intersect. |
Parallel planes | Planes that do not intersect. |
Transversal | Is a line that intersects two coplanar lines at two different points. |
Corresponding angles | Lie on the same side fo the transversal ( one on the interior and the other on the exterior). They are congruent. |
Alternate interior angles | Are non adjacent angles that lie on the opposite sides of the transversal. They are congruent. |
Alternate exterior angles | Lie on the opposite side of the transversal. They are congruent |
Same-side interior angles | Lie on the same side of the transversal. and the measure of the angles is equal , add up to 180° |
Corresponding Angle Postulate | If two lines are cut by a transversal, then the pairs of corresponding angles are congruent. |
Alternate interior angles theorem | If two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent. |
Alternate exterior angles theorem | When two parallel lines are cut by a transversal , the resulting alternate exterior angles are congruent . |
Same side interior angles theorem | when two lines that are parallel are intersected by a transversal line, the same-side interior angles that are formed are supplementary, or add up to 180 degrees. |
Parallel Postulate | Through a point p not on line l, there is exactly one line parallel to l |
Converse of the Alternate Interior Angles Theorem | If two coplanar lines are cut by a transversal so that a pair of alternate interior angles are congruent, then the two lines are parallel. |
Converse of the Alternate Exterior Angles Theorem | If two coplanar lines are cut by a transversal so that a pair of alternate exterior angles are congruent, then two lines are parallel. |
Converse of the Same-Side Interior Angles Theorem | If two coplanar lines are cut by a transversal so that a pair of same-side interior angles are supplementary, then the two lines are parallel. |
Converse of the Corresponding Angle Postulate | If two coplanar lines are cut by a transversal so that a pair of corresponding angles are congruent, then the two lines are parallel. |
Linear Pair Theorem | If two angles form a linear pair then they are supplementary. |
Parallel lines theorem | In a coordinate plane, two non vertical lines are parallel if and only if they have the same slope. Any two vertical lines are parallel. |
Perpendicular lines theorem | In a coordinate plane, two non vertical lines are perpendicular if and only if the product of their slope is -1. vertical and horizontal lines are perpendicular. |
The Slope of a Line | Is the ratio of the rise to run. If (x1,y1) and (x2 and y2) are any two points of the line, the slope of the line is m= y2 - y1 / x2 - x1. |
Slope | Is a line that describes the steepness of the line. |
Undefined | A fraction with zero as a denominator is undefined because it is impossible to divide a number by zero. |
Positive slope | Line comes from left to right |
Negative slope | Line comes from right to left |
0 slope | Line is horizontal |
VUX HOY | Vertical Undefined X only equation Horizontal 0 zero Y only |
Parallel | Have the same slope but different y intercept |
Coincide | |
Intersect | |
Perpendicular | Opposite in signs, they are recipricles of one another 3 = -3 |
Dilation | (x,y) - (kx, ky) , K> 0 |
Translation | (x,y) - (x + a, y + b) |
Reflection | (x,y) - (-x,y) reflection across y-axis (x,y) - (x,-y) reflection across x- axis |
Rotation | (x,y) - (y,-x) rotation about (0,0) 90° clockwise (x,y) - (-y,x) rotation about (0,0) 90° counter clockwise (x,y) - (-x,-y) rotation about 180° |
Scalene triangles | No sides are equal |
Acute triangles | Three acute angles |
Equiangular triangles | Three congruent acute acute angles |
Right triangle | One right angle |
Obtuse triangle | One obtuse angle |
Equilateral | Three congruent sides |
Scalene | No congruent sides |
Isoceles | Atleast two congruent sides |
SSS | If three sides of one triangle are congruent to three sides of another triangle, then the triangles are congruent. |
SAS | If two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle, then the triangles are congruent. |
ASA | |
AAS | |
HL |