geometry - angles with lines

acute angle

angle less than 90 degrees

obtuse angle

angle over 90 degrees but less than 180

reflex angle

angle over 180 degrees but less than 360

right angle

a 90 degree angle

scalene triangle

no sides or angles on the triangle are equal

isosceles triangle

two sides and two angles are equal

equilateral triangle

all 3 sides and angles in the triangle are equal

right angled triangle

a traingle containing a 90 degree angle

supplementary angles

two angles that add up to 180 degrees

complementary angles

two angles that add up to 90 degrees

angles on a line add up to

180 degrees

angles around a point add up to

360 degrees

vertically opposite angles are

equal

angles in a triangle add up to

180

the exterior angle of a triangle is equal to

the sum of the interior opposite angles

alternate angles on parallel lines are

the same

corresponding angles on parrallel lines are

equivalent

co-interior angles on parallel lines add up to

180 degrees (forms a c)