# Essential Geometry and Algebra Glossary

Classified in Mathematics

Written at on English with a size of 4.71 KB.

## Geometry

### Angles

**Adjacent angles** - that have a common vertex and side, but no common interior points

**Angle** - formed by two rays with a common endpoint called the vertex

**Complementary angles** - whose measures add up to 90°

**Congruent angles** - that have the same measure

**Supplementary angles** - two angles whose measures add up to 180°

**Vertical angles** - the nonadjacent angles formed by two intersecting lines

### Lines

**Midpoint** - the point that divides a segment into two congruent segments

**Parallel lines** - in a plane that never meet

**Perpendicular lines** - that intersect at 90° angles

**Transversal** - a line that intersects any two or more other lines

### Triangles

**Triangle Inequality Theorem** - the sum of the lengths of any two sides of a triangle is greater than the length of the third side

**Triangle Sum Theorem** - the angle measures of a triangle add up to 180°

### Transformations

**Congruent figures** - that have the same size and shape

**Congruence transformations**- that result in an image that is the same shape and the same size as the original.

**Image** - the resulting figure after a translation, rotation, or reflection

**Reflection** - flips a figure across a line to create a mirror image

**Rotation** - turns a figure around a point

### Three-Dimensional Figures

**Circumference** - the distance around the circle

**Cone** - a figure with a circular base

**Cylinder** - a three-dimensional figure with two circular, parallel, and congruent bases

**Hemisphere** - one of two halves of a sphere

**Prism** - a three- dimensional figure whose two bases are parallel congruent polygons and whose faces are parallelograms

**Pyramid** - a figure with one polygon base and triangular faces that meet at a point

**Regular pyramid** - a pyramid with a regular polygon for a base and congruent lateral faces

**Sphere** - A set of points in three dimensions that are a fixed distance from the center

## Algebra

### Expressions and Equations

**Equivalent expressions** - expressions that have the same value for all the values of the variables

**Like term** - terms that have the same variable raised to the same exponent

**Literal equation** - equation with two or more variables

**Simplify** - perform all the operations possible, including combining like terms

**Term** - elements of an expression that are separated by plus or minus signs

### Systems of Equations

**Solution of a system of equations** - set of values making all equations in a system true

**System of equations** - system of two or more equations that contain two or more variables

### Linear Equations

**Linear equation** - equation whose solutions fall on a straight line on the coordinate plane

**Point-slope form** - the equation of a line in the form of *y* - *y*_{1} = *m* (*x* - *x*_{1}), where *m* is the slope and (*x*_{1}, *y*_{1}) is a specific point on the line

**Slope** - the ratio of rise to run for any two points on a line

**Slope-intercept form** - a linear equation written in the form *y* = *mx* + *b*, where *m* is the slope and *b* is the y-intercept

** x-intercept** - the

*x*-coordinate of the point where the line crosses the

*x*-axis

** y-intercept** - the

*y*-coordinate of the point where the line crosses the

*y*-axis

### Variation

**Constant of variation** - the ratio by which two variable quantities are related

**Direct variation** - a relationship between two variables such that the data increase or decrease together at a constant rate

**Rate of change** - ratio that compares the amount of change in a dependent variable to the amount of change in an independent variable

**Rise** - the difference of the *y*-values of two points on a line

**Run** - the difference in the *x*-values of two points on a line