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