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Angle facts. P. R. ^. ^. PQR. and. RQS. Add up to 90 º. Two angles which make a RIGHT angle are. a º. COMPLEMENTARY. b º. a º is the complement of b º. Q. S. and b º is the complement of a º. a º + b º = 90 º.
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Angle facts P R ^ ^ PQR and RQS Add up to 90 º Two angles which make a RIGHT angle are a º COMPLEMENTARY b º a º is the complement of b º Q S and b ºis the complement of a º a º + b º = 90 º
the complements of the following angles are 73 º 80 º 54 º 10 º 17 º 36 º 9 º 33 º 40 º 81 º 57 º 50 º 84 º 35 º 45 º 6 º 55 º 45 º <ABD or <EBC A the complement of < DBC is D < EBC = 72 º the size of <DBC is 18 º C B the size of <ABD is 72 º E P14 ex 1A q 1,2,4,5,7 ex 1B
Supplementary angles H <EFH and <HFG add up to 180 º Two angles which make a STRAIGHT angle p º q º are G E F SUPPLEMENTARY a º is the supplement of b º and b ºis supplement of a º p º + q º = 180 º
the supplements of the following angles are 175 º 60 º 130 º 5 º 100 º 168 º 55 º 178 º 45 º 90 º 120 º 50 º 12 º 125 º 80 º 2 º 135 º 90 º The supplement of <AED is <ABC A The supplement of <CED is <CEB E D B <AED IS140 º <AEB is 40 º <DEC is 75 º <BEC is 105 º C P 16 EX 2A 1,2,5,6,7 AND EX 2B/C 1,2,3,4,
Vertically opposite angles B A Vertically opposite angles are found on opposite sides of a vertex E < AEB IS VERTICALLY OPPOSITE <DEC D C < AED IS VERTICALLY OPPOSITE <BEC
A bº + aº = 180º aº B E bº + cº = 180º D cº bº aº must be equal to cº C <AEB and <DEC are vertically opposite angles vertically opposite angles are equal <AED and <BEC Another pair of vertically opposite angles are EX 3A AND EX 3 B/C
To find vertically opposite angles we look for angles in an X shape
Corresponding angles A C B D E BC and DE are parallel lines Angles ABC and ADE are CORRESPONDING ANGLES F They are in the same position and they are equal
P An angle corresponding to <PQR is <TRS Q T x R x An angle corresponding to S 4 1 is 3 1 5 7 6 2 is 8 3 2 5 4 6 is 7 5 is Ex4a 1-4
This grid is made up two sets of parallel lines The red shape between the lines is a parallelogram The parm can slide along and down the grid > > > > > > > > > > >
All the parallelograms in the grid are CONGRUENT All the blue angles in the same position and are equal Equal angles in the same position are called CORRESPONDING ANGLES Find all the angles corresponding to the blue angle
Copy the diagrams.Mark the angles which are corresponding to the given ones with an x x x x x Ex4a 9 –11 ex 4b/c
Alternate angles A C B BC and DE are parallel lines D G E Angles CBG and BGD are ALTERNATE ANGLES F They are on opposite sides of the transverse line AF foundbetween the parallel lines
a c =100º b = 100 º a is vertically opposite c 100 º a= b is corresponding to a 100 º b= b is alternate to c b = c ALTERNATE ANGLES ARE EQUAL
p An angle alternate to <PQR is <QRT Q x x R An angle ALTERNATE to T S 4 7 is 3 1 6 7 6 3 is 8 8 2 5 Ex5a 1-6
Copy the diagrams Mark the angles which are alternate to the given ones with an x x x x x Ex 5A 7-12 Ex 5B/C