| A | B |
|---|
| arithmetic mean of two numbers a and b | 1/2(a + b) |
| dilation with center C and scale factor k | a transformation that maps every point P in the plane to a point P', so that the following properties are true. 1. If P is not point C, then ray CP is coincident with ray CP', and CP' = k(CP), where k > 0 and k does not equal 1. 2. If P is point C, then |
| enlargement | a dilation that has a scale factor k greater than 1. |
| geometric mean of two numbers a and b | the positive number x such that a/x = x/b. |
| proportion | an equation that equates two ratios |
| ratio | the comparison of two integers with the same units |
| reduction | a dilation that has a scale factor k between 0 and 1. |
| scale factor | the ration of corresponging linear measures in similar polygons |
| similar polygons | two polygons with corresponding angles congruent and corresponding sides proportional |
| cosine of an acute angle | the quotient of the length of the leg adjacent to the acute angle of a right triangle and the hypotenuse of the right triangle |
| Pythagorean triple | a set of three positive integers, a, b, and c, that satisfy the equation a^2 + b^2 = c^2 |
| sine of an acute angle | the quotient of the leg opposite the acute angle of the right triangle and the hypotenuse of the right triangle |
| tangent of an acute angle | the quotient of the leg opposite the acute angle and the leg adjacent to the acute angle of the right triangle |
| trigonometric ratio | a ratio of the lengths of two sides of a right triangle |
| central angle | an angle whose vertex is the center of the circle. |
| chord | a segment whose endpoints are on the circle |
| circle | the set ov all points in a plane that are equidistant from a given point. |
| circumscribed circle | a circle which contains each vertex of a polygon. |
| circumscribed polygon | a polygon with each side tangent to a circle |
| common external tangent | a common tangent that does not intersect the segment that joins the centers of the circles |
| common internal tangent | a common tangent that does intersect the segment that joins the centers of the circles |
| common tangent | a line that is tangent to two circles |
| concentric circles | coplanar circles that have the same center |
| congruent arcs | in the same circle or congruent circles arcs that have the same measure |
| congruent circles | two circles with congruent radii or congruent diameters |
| diameter | a chord that passes through the center |
| exterior of a circle | the points outside the circle |
| inscribed angle | an angle whose vertex is on the circle and whose sides contains chords of the circle |
| inscribed circle | a circle who is tangent to the sides of the polygon |
| inscribed polygon | a polygon whose sides are chords of the circle |
| interior of a circle | the points inside the circle |
| major arc | an arc associated with a central angle which contains all the points on the circle in the exterior of the central angle and the two points of the angle on the circle |
| minor arc | all the points that lie in the interior of a central angle and the two points of the angle that lie on the circle |
| point of tangency | the point at which the tangent intersects the circle |
| radius | a segment that has the center as one endpoint and a point on the circle as the other endpoint |
| secant | a line that intersects the circle in two points |
| semicircle | an arc whose endpoints are the endpoints of a diameter |
| standard equation of a circle | (x - h)^2 + (y - k)^2 = r^2 with radius r and center (h, k) |
| tangent | a line that intersects a circle in exactly one point |
| apothem | the distance between the center of a regular polygon and a side |
| area | the number of square units contained in the interior of a polygon |
| center of a regular polygon | the center of the circumscribed circle |
| central angle of a regular polygon | an angle whose vertex in the center and whose sides contain two consecutive vertices of the polygon |
| circumference | the product of the length of the diameter of a circle and pi |
| perimeter of polygon | the sum of the lengths of the sides of a polygon |
| radius of a regular polygon | a segment whose endpoints is the center and a vertex of the polygon |
| sector | the region bounded by two radii of the circle and their intercepted arc |
| segment of a circle | a region bounded by a chord and its intercepted arc |
| chord of a sphere | a segment whose endpoints are on the sphere |
| cone | a solid that has a circular base and a vertex that is not in the same plane as the base |
| convex polyhedron | a polyhedron in which any two points on its surface can be connected by a line segment that lies entirely inside or on the polyhedron |
| cylinder | a solid with congruent circular bases that lie in parallel planes |
| diameter of a sphere | a chord that contains the center of the sphere |
| dodecahedron | a 12 faced polyhedron |
| great circle | the intersection of a plane and a sphere that contains the center of the sphere |
| hemisphere | a part of a sphere made by a great circle |
| icosahedron | a 20 faced polyhedron |
| lateral area of a cylinder | the area of its curved lateral surface |
| oblique prism | prisms that have lateral edges that are oblique to the bases of the prism |
| octahedron | a 8 faced polyhedron |
| polyhedron | a solid that is bounded by polygons, called faces, that enclose a single region of space |
| prism | a polyhedron that has two parallel, congruent faces called bases |
| pyramid | a polyhedron in which the base is a polygon and the lateral faces are triangles that have a commong vertex |
| radius of a sphere | a segment whose endpoints are the center of the sphere and a point on the sphere |
| regular polyhedron | a polyhedron in which all its faces are congruent regular polygons and the same number of faces meet at each vertex in exactly the same way. |
| regular pyramid | a pyramid whose base is a regular polygon and the segment from the vertex to the center of the base is perpendicular to the base |
| right cone | a cone in which the vertex lies directly above the center of the base |
| right cylinder | a cylinder in which the segment joining the centers of its bases is perpendicular to its bases |
| right prism | a prism in which each lateral edge is perpendicular to both bases |
| semiregular polyhedron | a polyhedron whoses faces are more than one type of regular polygon and whose vertices are all exactly the same |
| similar solids | two solids whose ratios of corresponding linear measures are equal |
| sphere | the set of points equidistant from a given point |
| surface area of a polyhedron | the sum fo the areas of its faces |
| surface of a polyhedron | consists of all points on its faces |
| tetrahedron | a 4 faced polyhedron |
| volume | the number of cubic units contained in a solid's interior |
| compound locus | the intersection loci given by two or more conditions |
| conic section | the intersections of a plane and a double napped right cone |
| cross section | the intersection of a plane and a solid |
| ellipse | the locus of points (x, y) such that the sum of the distances between (x, y) and two distinct given points, the foci, is a constant |
| locus | is the set of all points that satisfy a given condition or set of given conditions |
