7-4, Classifying Triangles and Quadrilaterals (8.G.1, 8.G.2, and 8.G.3)
acute triangle - three acute angles
obtuse triangle - one obtuse angle
right triangle - one right angle
equilateral triangle - three congruent sides
isosceles triangle - at least two congruent sides
scalene triangle - no congruent sides
quadrilateral - four sides
trapezoid - exactly one pair of parallel sides
parallelogram - both pairs of opposite sides parallel
rhombus - four congruent sides
rectangle - four right angles
square - four right angles and four congruent sides
obtuse triangle - one obtuse angle
right triangle - one right angle
equilateral triangle - three congruent sides
isosceles triangle - at least two congruent sides
scalene triangle - no congruent sides
quadrilateral - four sides
trapezoid - exactly one pair of parallel sides
parallelogram - both pairs of opposite sides parallel
rhombus - four congruent sides
rectangle - four right angles
square - four right angles and four congruent sides
Classifying Quadrilaterals (4:33)
Classifying Triangles (7:39)