radius
A line segment that joins the center of a circle with any point on its circumference.
complementary angles
Two angles whose sum is 90°.
supplementary angles
two angles that add up to 180 degrees.
cross-section
a cutting or piece of something cut off at right angles to an axis
diameter
any straight line segment that passes through the center of the circle and whose endpoints lie on the circle.
circumference
The boundary line of a circle.
volume
a measure of regions in three-dimensional space.
adjacent angles
angles that have a common arm (side) and a common vertex, however, they do not overlap.
Triangle Inequality Theorem
the triangle inequality states that for any triangle, the sum of the lengths of any two sides must be greater than or equal to the length of the remaining side
surface area
The surface area of a solid object is a measure of the total area that the surface of the object occupies.
vertical angles
Whenever two lines cross or intersect each other, four angles are formed. Out of these, the angles opposite to each other are called vertical angles or vertical