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AC. AB. CB. l ine n. AB. AC. BC. XY. XZ. YZ. YX. ZX. ZY. SY. ST. YT. YS. TS. TY. collinear. Points A, B, and F are coplanar and NOT collinear. E is not on plane R. D is not on plane R. collinear. E is not on plane R. Points B, C, and F are coplanar and NOT collinear.
E N D
AC AB CB line n
AB AC BC
XY XZ YZ YX ZX ZY SY ST YT YS TS TY
D is not on plane R collinear E is not on plane R
RSU UST RST
Two planes intersect at a line. GF or line l
DH AE
DH AE EH AE
DH AE EH AE & EF BC There is no symbol for skew.
DH AE EH AE & EF BC Plane ABC Plane EFG
140o – 15o = 125o 140o 15o
A 56o 16o B D xo 16o + xo = 72o (angle addition postulate) C xo = 56o (subtraction: subtract 16)
bisects – divides into two congruent parts A 5 4(5) – 3 = 17o (4x – 3)o B D (2x + 7)o 2(5) + 7 = 17o 17o + 17o = 34o C 4x – 3 = 2x + 7 (bisects) 2x – 3 = 7 (subtraction: subtract 2x) 2x = 10 (addition: add 3) x = 5 (division: divide by 2)
46 6 A C B 3(6) = 18 5x – 2 3x 5(6)– 2 = 28 3x + 5x – 2 = 46 (segment addition postulate) 8x – 2 = 46 (simplify: add 3x and 5x) 8x = 48 (addition: add 2) x = 6 (division: divide by 8)
A 11 3+ 11 = 14o (x + 3)o B D (3x – 9)o 3(11) – 9 = 24o 14o+ 24o= 38o C x + 3 + 3x – 9 = 38 (angle addition postulate) 4x – 6 = 38 (simplify: combine like terms) 4x = 44 (addition: add 6) x = 11 (division: divide by 4)
midpoint– divides a segment into two congruent parts 3 14x – 10 3(3) + 7 = 16 A C B 3x + 7 3x + 7 (same as AB) 16 14(3) - 10 = 32 3x + 7 + 3x + 7 = 14x – 10 (segment addition postulate) 6x + 14 = 14x – 10 (simplify: add like terms) 14 = 8x – 10 (subtraction: subtract 6x) 24 = 8x (addition: add 10) x = 3 (division: divide by 8)
A complementary– two angle add up to 90o 62.5o 27.5o B C 27.5 + x = 90 (complementary: add to 90) X x = 62.5 (subtraction: subtract 27.5) xo Y Z
supplementary– two angle add up to 180o 42o 3(42) + 12 = 138o 180 – 138 = 42o 3x + 12 + x = 180 (supplementary: add to 180) 4x + 12 = 180 (simplify: add like terms) 4x = 168 (subtraction: subtract 12) x = 42 (division: divide by 4)