Geometry Terms 4th grade

An angle that is less than 90 degrees

• obtuse angle

• straight angle

• acute angle

• right angle

a four-sided polygon

• quadrilateral

• polygon

• parallelogram

• rectangle

a triangle with at least two congruent sides

• scalene triangle

• equilateral triangle

• isosceles triangle

• right triangle

A triangle with three congruent sides

• scalene triangle

• right triangle

• isosceles triangle

• equilateral triangle

line in the same plane that never intersect

• perpendicular lines

• parallel lines

• intersecting lines

• obtuse lines

an angle that measures 180 degrees

• right angle

• obtuse angle

• acute angle

• straight angle

lines that intersect to form right angles

• perpendicular lines

• parallel lines

• intersecting lines

• acute lines

an angle that measures 90 degrees

• obtuse angle

• straight angle

• acute angle

• right angle

a closed figure formed by three or more line segments

• quadrilateral

• rhombus

• polygon

• parallelogram

a triangle with one obtuse angle

• acute triangle

• right triangle

• obtuse triangle

• equilateral triangle