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40 terms

Math vocabulary for grade 3 as presented in MCP math book.

Polygons

Plane figures like squares and triangles

Acute angle

An angle that has less of an opening than a right angle

Acute triangle

A triangle with 3 acute angles

Angle

A figure formed by two rays that have the same endpoint; the endpoint is called the vertex

Pentagon

A plane figure with 5 sides

Hexagon

A plane figure with 6 sides

Octagon

A plane figure with 8 sides

Area

The number of square units it takes to cover the surface of a plane figure

Line of symmetry

Divides a figure into 2 parts so that both parts match exactly

Face

Flat surface on a pyramid, cube or prism.

Volume

The number of cubic units it takes to fill a solid figure

Point

A position in space

Line segment

Part of a line with 2 endpoints

Ray

Part of a line.....1 endpoint

Horizontal line

Line that goes across

Vertical line

A line that goes up and down

Intersecting lines

Lines that meet at 1 point

Parallel lines

Lins that do not intersect in the same plane, or flat surface

Right angle

An angle that forms a square corner

Obtuse angle

Has a greater opening than a fit angle but less than a straight line

Perpendicular

Lines, line segments or rays that form right angles

Angle

2 rays that have a common endpoint

Vertex

Common endpoint of an angle

Equilateral triangle

All sides same length

Isosceles triangle

At least 2 sides are the same length

Scalene triangle

None of the sides are the same length

Right triangle

1 angle is a right angle

Acute triangle

All 3 angles are acute angles

Obtuse triangle

1 angle is an obtuse angle

Quadrilateral

Quad means 4- four sides and 4 angles

Rhombus

Opposite sides are parallel and all sides are the same length

Trapezoid

1 pair of parallel sides only

Rectangle

4 right angles and opposite sides are the same length

Square

4 right angles and all sides are the same length

Parallelogram

Opposite sides are parallel a nd the same length .

Congruent

"the same"- plane figures that are the same size and shape are called congruent figures

Slide

Moves a figure a given distance and a given direction. Another name for slide is a translation.

Flip

A flip moves a figure over a line to get a mirror image. Another name for a flip is a reflection.

Turn

A turn rotates a figure clockwise or counterclockwise. Another name for a turn is a rotation.

Transformation

Moving a figure in a slide, flip or turn without changing its shape or size.