46 terms

Line

Continues forever in both directions

Line segment

Ends in both directions

Ray

Continues forever in one direction

Obtuse angle

An angle greater than 90 degrees

Right angle

An angle exactly 90 degrees

Acute angle

An angle less than 90 degrees

Polygon

A shape that has at least 3 sides, is closed, has no line segments that cross, and has only straight line segments, like a triangle or quadrilateral

Circle

A perfectly round 2D shape

Triangle

A 3-sided polygon

Quadrilateral

A 4-sided polygon

Pentagon

A 5-sided polygon

Hexagon

A 6-sided polygon

Heptagon

A 7-sided polygon

Octagon

An 8-sided polygon

Nonagon

A 9-sided polygon

Decagon

A 10-sided polygon

Acute triangle

A triangle with 3 acute angles

Obtuse triangle

A triangle with 1 obtuse angle

Right triangle

A triangle with 1 right angle

Parallelogram

A quadrilateral with 2 pairs of parallel sides

Trapezoid

A quadrilateral with 1 pair of parallel sides

Rectangle

A parallelogram with 4 right angles

Rhombus

A parallelogram with 4 equal sides

Square

A rectangle with 4 equal sides; it is a rhombus, a rectangle, a parallelogram, and a quadrilateral

Kite

A quadrilateral with 2 sides the same length right next to each other, and 2 other sides the same length right next to each other

Equilateral triangle

A triangle with 3 equal sides

Isosceles triangle

A triangle with 2 equal sides

Scalene triangle

A triangle with all 3 sides different lengths

Polyhedron

A 3D shape made of polygons

Prism

A polyhedron with sides that are rectangles

Cube

A prism that has all sides squares

Cylinder

A 3D shape with 2 bases that are circles

Sphere

A 3D shape like a 3D circle

Pyramid

A polyhedron with all sides triangles

Face

The flat side of a 3D shape

Vertex/vertices

Where 3 or more faces meet, like a corner

Edge

Where 2 faces meet

Volume

The space inside a 3D shape, the length x width x height

Area

The space inside a 2D shape, the length x width, like the area of a carpet

Perimeter

The length around a 2D shape, like a fence around something

Symmetry

When it looks the same on both sides, or would look identical if you turned it

Similar

The same shape, but can be different sizes

Congruent

The exact same shape and size, but can be turned

Parallel

Two lines that will never cross

Perpendicular

Two lines that cross to form right angles

Intersect

Two lines that cross, could be perpendicular, could be any other angle as long as they will cross