Angles
this angle is less than 90 degrees
what is acute
two intersecting lines that form 90 degree angles
what are perpendicular
a triangle with one 90 degree angle
what is right
the perimeter of a circle
what is circumference
having the same size and shape
the common endpoint of the two rays that form an angle
what is the vertex
lines in the same plane that never intersect
what are parallel lines
a triangle with three congruent sides
what is equilateral
the point that is the same distance from all the points on the circle
what is the center
figures with the same shape but not necessarily the same size
what is similar
this angle is 180 degrees
what is straight
part of a line that has one endpoint and extends forever in one direction
what is a ray
the measures of the angles of a triangle add up to this
what is 180 degrees
a line segment that passes through the center of the circle
what is the diameter
the distance around a geometric figure
what is perimeter
this angle measures exactly 90 degrees
what is right
part of a line that extends from one endpoint to another endpoint
what is a line segment
formula for finding the area of a triangle
what is base times height divided by two
line segment with one endpoint at the center and one endpoint on the circle
what is the radius
two angles whose measures add to 180 degrees
what is supplementary
this angle measures more than 90 degrees but less than 180 degrees
what is obtuse
lines that do not intersect and are also not parallel
what are skew lines
a triangle with two congruent sides
what is isosceles
formula for calculating the circumference
what is PI times diameter
what is complementary