28 terms

3rd Grade Geometry Vocabulary

3rd grade Geometry Vocabulary with term definitions.
STUDY
PLAY
Square
A quadrilateral with 4 equal sides and 4 vertices that form right angles.
Opposite sides are parallel.
Rectangle
A quadrilateral with 4 sides and 4 vertices that form right angles.
Opposite sides are equal and parallel.
Triangle
A polygon with 3 sides and 3 vertices.
Circle
A plane shape made with a continuous line which is always the same distance from the center. It has no sides and no vertices.
Line
A straight path that goes without end in opposite directions.
Line Segment
Part of a line with two end points.
Right Angle
A 90 degree angle that makes a square corner.
Side
Line segments of a polygon.
Vertex
The point where two sides meet.
Quadrilateral
Any polygon with 4 sides and 4 angles.
Parallelogram
Any quadrilateral with opposite parallel sides. Example: rectangle, rhombus, square
Trapezoid
A quadrilateral with one pair of parallel sides.
Rhombus
A parallelogram with four equal sides and equal opposite angles.
Congruent
A plane figure with the same size and shape.
Symmetry
A plane figure that can be folded along a line so the two parts match.
Line of Symmetry
The line that divides two matching parts. It can be vertical, horizontal, or diagonal.
Perimeter
The distance around the figure.
Area
The size a surface takes up, measured in square units.
Rectangular Prism
A solid shape that has: 6 faces (4 rectangles & 2 squares), 8 vertices, and 12 edges.
Cube
A solid shape that has: 6 square faces all equal in size, 8 vertices, and 12 equal edges.
Sphere
A solid shape that is perfectly round like a ball. No faces, edges, or vertices.
Cone
A solid shape with a circular base, 1 curved edge, and a curved surface that comes to a point (vertex or apex).
Cylinder
A solid shape with one curved surface, 2 curved edges and two circular bases.
Pyramid
A solid shape with a polygon as a base and triangular faces that come to a point (vertex or apex)
Face
The flat surface of a 3D shape.
Edge
Where two faces meet (intersect).
Plane shape
A flat closed shape having only 2 dimensions.
Parallel Lines
Lines that do not cross (intersect) and are always the same distance apart.
YOU MIGHT ALSO LIKE...