How can we help?

You can also find more resources in our Help Center.

right angle

angle that is 90˚

acute angle

angle that is less than 90˚

obtuse angle

angle that is more than 90˚

straight angle

180˚

complementary

two angles that equal 90˚

supplementary

two angles that equal 180˚

adjacent

angles that are right next to each other

vertical

congruent (X)

transversal

a line that crosses two or more lines

corresponding

___________ angles are the same. They are congruent.

alternate interior

congruent (hint: ≠)

isosceles

a triangle with two equal sides

equilateral

a triangle with all equal sides

scalene

a triangle with NO equal sides

acute

a triangle with all acute angles

right

a triangle with a right angle

obtuse

a triangle with an obtuse angle

quadrilateral

4 sided polygon

trapezoid

quadrilateral with one pair of parallel lines

parallelogram

quadrilateral with two sets of parallel lines

rectangle

parallelogram with 4 right angles

rhombus

parallelogram with 4 congruent sides

square

parallelogram with 4 congruent sides and 4 right angles

polygon

geometric figure with 3 or more line segments that intersect only at their endpoints.

regular polygon

polygon with all congruent sides and all congruent angles

hexagon

6 sided polygon-720˚

heptagon

7 sided polygon-900˚

octagon

8 sided polygon-1080˚