# vocabulary

### math vocabulary ## area

the size of a surface ## perimeter

the distance around a two-dimensional shape. ## exterior angle

the angle between any side of a shape, and a line extended from the next side. ## dilation

where the polygon grows or shrinks but keeps the same overall shape. ## scale factor

a number which scales, or multiplies, some quantity. ## Corresponding Angles

When two lines are crossed by another line ## Line of Symmetry

does not have to be up-down or left-right, it can be in any direction. ## acute angle

is less than 90° ## Obtuse Angle

is more than 90° but less than 180° ## Perimeter

is the distance around a two-dimensional shape. ## Vertical Angles

the angles opposite each other when two lines cross. ## Congruent

If one shape can become another using Turns, Flips and/or Slides, then the shapes are Congruent ## Trapezoid

is a 4-sided flat shape with straight sides that has a pair of opposite sides parallel ## Radius

The distance from the center to the edge of a circle

It is half of the circle's diameter. ## Diameter

A straight line going through the center of a circle connecting two points on the circumference ## Surface Area

The total area of the surface of a three-dimensional object ## Volume

The amount of 3-dimensional space an object occupies. Capacity. 