# 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 - y1 = m (x - x1), where m is the slope and (x1, y1) 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