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Perpendicular and angle bisectors. Geometry (Holt 5-1) K. Santos. Perpendicular Bisector Theorem (and converse). If a point is on the perpendicular bisector of a segment, then it is equidistant from the endpoints of the segment. X Given: is the perpendicular
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Perpendicular and angle bisectors Geometry (Holt 5-1) K. Santos
Perpendicular Bisector Theorem (and converse) If a point is on the perpendicular bisector of a segment, then it is equidistant from the endpoints of the segment. X Given: is the perpendicular bisector of A B Then: XA = XB Y
Example—Perpendicular Bisector Find MN. N 2.6 M L MN = NL since NL = 2.6 then MN = 2.6
Example—Perpendicular Bisector B Find BC. 38 D A 12 38 C BD = DC So BD = 12 BC = BD + DC BC = 12 + 12 BC =24
Example—Perpendicular Bisector U Find TU 3x + 9 7x - 15 T W V UV = TU 7x -15 = 3x + 9 4x – 15 = 9 4x = 24 x = 6 TU = 3x + 9 TU = 3(6) + 9 = 27
Angle Bisector Theorem (and converse) If a point is on the bisector of angle, then it is equidistant from the sides of the angle. Given: bisects <APB A P C Then: AC = BC B
Example—Angle Bisector Find BC B CD = 7.2 A C D BC = CD Since CD = 7.2 then BC = 7.2
Example—Angle Bisector F Find m< EFH. m< EFG = 50 E G H m< EFG = 50 m < EFH = ½ m<EFG m < EFH = ½(50) = 25
Example—Angle Bisector K 2a + 26 Find m <MKL. L 3a +20 J M m < JKM = m <MKL 3a + 20 = 2a + 26 a + 20 = 26 a = 6 m< MKL = 2a + 26 m< MKL = 2(6) + 26 = 38