40 terms

# MCP Mathematics- Grade 3 geometry

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