Geometry Terms

A five sided polygon.

• Octagon

• Trapezoid

• Pentagon

• Hexagon

A triangle with one obtuse angle (more than 90 degrees).

• Right triangle

• Obtuse triangle

• Isosceles triangle

• Scalene triangle

A triangle with no congruent sides. All sides are different lengths.

• Equilateral triangle

• Acute triangle

• Obtuse triangle

• Scalene triangle

One angle that measures exactly 180 degrees.

• straight angle

• obtuse angle

• Supplementary angle

• central angle

The sum of these angles equals exactly 180 degrees.

• Complementary angles

• acute angle

• Supplementary angles

• straight angle

A quadrilateral that has at least 1 pair of opposite sides that are parallel.

• Quadrilateral

• Trapezoid

• Rectangle

• Parallelogram

A triangle with three acute angles.

• Isosceles triangle

• Right triangle

• Acute triangle

• Obtuse triangle

Lines that share a common point, but not right angles.

• Parallel lines

• Intersecting, not perpendicular lines

• Straight lines

• Perpendicular lines

Two rays sharing an endpoint or vertex.

• angle

• perpendicular lines

• Vertex

• Supplementary angles

The sum of these angles equals exactly 90 degrees.

• central angles

• Supplementary angles

• straight angles

• Complementary angles