Basic Geometry Vocabulary Flashcards
Polygon
Closed figure with straight sides
Quadrilateral
4- sided polygon
Trapezoid
A quadrilateral with only one set of parallel lines
Parallelogram
A quadrilateral with two sets of parallel lines
Rhombus
A parallelogram (two sets of parallel sides) with all sides the same length
Rectangle
A parallelogram (two sets of parallel sides) with four right angles, opposite sides are of equal length
Square
A rhombus (2 sets of parallel lines, all sides of equal length) with four right angles
Acute Triangle
A triangle that has all angles less than 90° (90° is a Right Angle)
Right Triangle
A triangle that has a right angle (90°)
Obtuse Triangle
A triangle that has an angle greater than 90°
Equilateral Triangle
A triangle with all three sides of equal length.
All angles are acute.
Isosceles Triangle
A triangle with two equal sides.
The angles opposite the equal sides are also equal.
Scalene Triangle
A triangle with all sides of different lengths.
All angles are
different, too.
Pentagon
5-sided polygon
Heptagon
7-sided polygon
Hexagon
6-sided polygon
Octagon
8-sided polygon
Decagon
10- sided polygon