An angle that measures exactly 90 degrees, forming a perfect corner.
right angle
An angle that measures less than 90 degrees; it is sharper and smaller than a right angle.
acute angle
An angle that measures more than 90 degrees but less than 180 degrees; it is wider than a right angle.
obtuse angle
A part of a line that has one endpoint and extends infinitely in one direction.
ray
A part of a line that has two endpoints and is a fixed length.
line segment
A closed shape made up of straight lines, with at least three sides, such as triangles and squares.
polygons
A round shape where all points are the same distance from the center point; it has no corners.
circle
The distance from the center of a circle to any point on its edge; it is half the diameter.
radius
A straight line that passes through the center of a circle and connects two points on its edge; it is twice the length of the radius.
diameter
A tool used to measure angles in degrees
protractor
A type of polygon that has four sides, such as squares and rectangles.
Quadrilateral
Lines that run side by side and never intersect, no matter how far they are extended.
Parallel lines
Lines that intersect at a right angle (90 degrees).
Perpendicular Lines
An angle that measures exactly 180 degrees, appearing as a straight line.
straight angle
An angle that measures 0 degrees, meaning there is no space between the two rays
zero angle
