Question | Answer |
intersecting lines | lines that cross each other at exactly one point |
parallel lines | lines in the same plane that never intersect and are always the same distance apart |
perpendicular lines | two lines that intersect to form four right angles |
polygon | a closed plane figure formed by three or more straight sides that are line segments |
triangle | a polygon with three sides and three angles |
quadrilateral | a polygon with four sides and four angles |
pentagon | a polygon with five sides and five angles |
hexagon | a polygon with six sides and six angles |
octagon | a polygon with eight sides and eight angles |
decagon | a polygon with ten sides and ten angles |
regular polygon | a polygon that has sides that are the same length |
parallelogram | a quadrilateral whose opposite sides are parallel and equal, or congruent |
rhombus | a parallelogram with four equal, or congruent sides |
trapezoid | a quadrilateral with exactly one pair of parallel sides |
equilateral triangle | a triangle with three equal sides |
isosceles triangle | a triangle with two equal sides |
scalene triangle | a triangle with no equal sides |
right triangle | a triangle with one right angle |
acute triangle | a triangle with three acute angles |
obtuse triangle | a triangle with one obtuse angle |