8/31/11 SECTION 1.4 WORD Midpoint 9/2/11 1.5 Perpendicular Bisector 9/7/11 2.5 Adjacent Angles 9/9/11 2.5 Complementary Angles 9/13/15 2.5 Supplementary Angles 9/15/11 9/20/11 2.5 2.5 Theorem Vertical Angles 9/22/11 3.1 Alternate Interior Angles 9/27/11 3.1 Corresponding Angles 9/29/11 3.1 Transversal 10/4/11 5.3 Centroid 10/6/11 5.3 10/11/11 5.1 Circumcenter of a triangle Midsegment 10/13/11 5.3 Orthocenter of a triangle 10/18/11 6.7 Midsegment of a trapezoid 10/20/11 7.5 Apothem of a regular polygon Arc Length 10/25/11 7.6 DEFINITION A midpoint of a line segment is the point that divides the segment into two congruent segments. The perpendicular bisector of a segment is a line, segment, or ray that is perpendicular to the segment at its midpoint. Adjacent angles are two coplanar angles that have a common side and a common vertex but no common interior points. Two angles are complementary angles if the sum of their measure is 90. Two angles are supplementary if the sum of their measures is 180. A theorem is a conjecture that is proven. Vertical angles are two angles whose sides form two pairs of opposite rays. Alternate Interior angles are nonadjacent interior angles that lie on opposite sides of the transversal. Corresponding angles lie on the same side of the transversal t and in corresponding positions relative to l and m. A transversal is a line that intersects two coplanar lines in two points. The centroid of a triangle is the point of intersection of the medians of that triangle. P is the centroid of โABC. A circumcenter is the point of concurrency of the perpendicular bisectors of a triangle. A midsegment of a triangle is the segment that joins the midpoints of two sides of the triangle. The orthocenter of a triangle is the point of intersection of the lines containing the altitudes of the triangle. The midsegment of a trapezoid is the segment that joins the midpoints of the nonparallel opposite sides of the trapezoid. The apothem of a regular polygon is the distance from the center to a side. The length of an arc of a circle is the product of the ๐๐๐๐ ๐ข๐๐ ๐๐ ๐กโ๐ ๐๐๐ 10/27/11 7.6 Central Angle 11/1/11 7.6 Circumference 11/3/11 7.1 Height of a Triangle 21 7.6 Pi ratio and the circumference of 360 the circle. A central angle of a circle is an angle whose vertex is the center of the circle. The circumference of a circle is the distance around the circle. Given the radius r of a circle, you can find its circumference C by using the formula C = 2๐r. The height of a triangle is the length of the altitude to the line containing that base. Pi (๐ ) is the ratio of the circumference of any circle to its diameter. The number ๐ is irrational and is approximately 3.14159. 22 7.7 Sector of a Circle 23 7.7 Segment of a Circle 24 25 7.6 8.2 Semicircle Golden Rectangle 26 9.2 Cosine A sector of a circle is the region bounded by two radii and their intercepted arc. A segment of a circle is the part of a circle bounded by an arc and the segment joining its endpoints. A semicircle is half a circle. A golden rectangle is a rectangle that can be divided into a square and a rectangle that is similar to the original rectangle. The cosine in a right triangle โABC with acute angle โขA. cosine โขA = cos A = 27 9.2 Sine The sine in a right triangle โABC with acute angle โขA. sine โขA = sin A = 28 9.1 Tangent ๐๐๐ ๐๐๐๐๐๐๐๐ก โข ๐ด โ๐ฆ๐๐๐ก๐๐๐ข๐ ๐ ๐๐๐ ๐๐๐๐๐ ๐๐ก๐ โข ๐ด โ๐ฆ๐๐๐ก๐๐๐ข๐ ๐ The tangent in a right triangle โABC with acute ๐๐๐ ๐๐๐๐๐ ๐๐ก๐ โข ๐ด angle โขA. tangent โขA = tan A = ๐๐๐ ๐๐๐๐๐๐๐๐ก โข ๐ด 29 10.3 Altitude 30 10.3 Base 31 10.4 Cone 32 10.3 Cylinder 33 10.3 Lateral Area 34 10.3 Prism An altitude of a prism is a perpendicular segment that joins the planes of the bases. An altitude of a triangle is a perpendicular segment from a vertex to the line containing the side opposite that vertex. In a prism there are exactly two congruent parallel faces, which are also called bases. The bases in a trapezoid are the two sides that are parallel but not congruent. A cone is a three-dimensional figure that has a circular base, a vertex not in the plane of the circle, and a curved lateral surface. The altitude of a cone is the perpendicular segment from the vertex to the plane of the base. The height is the length of the altitude. In a right cone, the altitude contains the center of the base. The slant height of a right cone is the distance from the vertex to the edge of the base. A cylinder is a three-dimensional figure with two congruent circular bases that lie in parallel planes. An altitude of a cylinder is a perpendicular segment that joins the planes of the bases. Its length is the height of the cylinder. In a right cylinder, the segment joining the centers of the bases is an altitude. In an oblique cylinder, the segment joining the centers of the bases is not perpendicular to the planes containing the bases. The lateral area of a prism or pyramid is the sum of the areas of the lateral faces. The lateral area of a cylinder or cone is the area of the curved surface. A prism is a polyhedron with two congruent and parallel faces, which are called the bases. The other faces, which are parallelograms, are called the lateral faces. An altitude of a prism is a perpendicular segment that joins the planes of the bases. Its length is the height of the prism. A right prism is one whose lateral faces are rectangular regions and a lateral edge is an altitude. In an 35 10.4 Pyramid 36 10.4 Slant Height 37 10.7 Sphere 38 39 11.2 10.5 Volume Chord oblique prism, some or all of the lateral faces are nonrectangular. A pyramid is a polyhedron in which one face, the base, is a polygon and the other faces, the lateral faces, are triangles with a common vertex, called the vertex of the pyramid. An altitude of a pyramid is the perpendicular segment from the vertex to the plane of the base. Its length is the height of the pyramid. A regular pyramid is a pyramid whose base is a regular polygon and whose lateral faces are congruent isosceles triangles. The slant height of a regular pyramid is the length of an altitude of a lateral face. The slant height of a regular pyramid is the length of an altitude of a lateral face. A sphere is the set of all points in space a given distance r, the radius, from a given point C, the center. A great circle is the intersection of a sphere with a plane containing the center of the sphere. The circumference of a sphere is the circumference of any great circle of the sphere. Volume is a measure of the space a figure occupies. A chord of a circle is a segment whose endpoints are on the circle. 40 11.4 Secant A secant is a line , ray, or segment that intersects a circle at two points.