An Angle that measure less than 90 degrees.

A box shape in three dimensional space. Formally, a polyhedro n for which all faces are rectangles.

A three- dimensional geometric figure with parallel cong ruent bases. The bases can be shaped like any closed plane figure not necessarily a circle and must be oriented identically.

The collective term for all bounded three-dimensional geometric figures. This includes polyhedr ons pyramids, prisms, cylinders, cones, s pheres, ellipsoids etc.

A polygon with six sides

has largest possible circle that can be drawn interior t o a plane figure. For a polygon a circle is not actually inscribed unless each side of the polygon is tangent to the circle.

The largest possible circle tha t can be drawn interior to a plane figure. For a polygon a circle is not actually inscribed unless each side of the polygon is tangent to the circle.

The inverse function of tan gent

A trapezoid with base angles th at are the same. Consequently, the legs will be congruent t o each other as well.

A quadrilatera l with two pairs of adjacent si des that are congruent. Note that the diagonals of a kite are perpendicular.

The shorter of the two arcs betw een two points on a circl e.

An egg- shaped curve

A polygon with five sides.

The distance around the outside of a plane figure. For a polygon the perimeter is the sum of the lengths of the sides.

A parallelogra m with four congruent sides. Note that the diagonals of a rhombus …are perpendi cular(as is the case with all kites).

The ratio of any two corresponding lengths in two similar geome tric figures Note: The ratio of areas of two similar figures is the square of the scale factor. The ratio of volumes of two similar figures is the cube of the scale factor.

Half a circle. That is, a 180° arc.

A doughnut shape. Formally, a torus is a surface of revolution obtained by revolving (in three dimensional space) a circle about a line which does not intersect the circle.

The property of a point that indicates no motion is possible without leaving that point. Formally, saying a point has zero dimensions means that the only vector contained on the point is the zero vector