3rd Grade Math Vocabulary

Two lines that meet to form a square corner at exactly 90 degrees.

• acute angle

• straight angle

• right angle

• obtuse angle

Any of the numbers that are added together.

• product

• addend

• factor

• sum

An arrangement going up and down. Upright.

• vertical

• horizontal

• parallel

• diagonal

The half of the day between 12:00 midnight and 12:00 noon.

• p.m.

• f.m.

• a.m.

• afternoon

A point where two or more straight lines meet. A corner.

• vertex

• edge

• side

• face

A solid object that has a circular base and one vertex (point).

• cone

• triangular prism

• pyramid

• cylinder

A four-sided figure with one pair of parallel sides and one pair of sides that are not parallel.

• rhombus

• pentagon

• trapezoid

• pyramid

The space between two lines that meet at a common vertex (point).

• vertex

• ray

• face

• angle

Flat shapes that have width and height but no thickness.

• parallelograms

• quadrilaterals

• two-dimensional

• three-dimensional

The number of square units covering the inside of a plane figure.

• width

• area

• length

• perimeter