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ANGLES OF POLYGONS. SPI 3108.4.3 Identify, describe and/or apply the relationships and theorems involving different types of triangles, quadrilaterals and other polygons. JIM SMITH JCHS. POLYGONS. NOT POLYGONS. CONCAVE. CONVEX. TRY THE PEGBOARD AND RUBBER BAND TEST.
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ANGLESOFPOLYGONS SPI 3108.4.3 Identify, describe and/or apply the relationships and theorems involving different types of triangles, quadrilaterals and other polygons. JIM SMITH JCHS
POLYGONS NOT POLYGONS
CONCAVE CONVEX TRY THE PEGBOARD AND RUBBER BAND TEST
NAMES OF POLYGONS SIDES TRIANGLE 3 QUADRILATERAL 4 PENTAGON 5 HEXAGON 6 HEPTAGON 7 OCTAGON 8 NONAGON 9 DECAGON 10 DODECAGON 12 N – GON N SEE PAGE 46 IN TEXTBOOK
INTERIOR ANGLE SUM OF CONVEX POLYGONS FIND THE NUMBER OF TRIANGLES FORMED BY DIAGONALS FROM ONE VERTEX 6 SIDES = 4 TRIANGLES
INTERIOR ANGLE SUM FIND THE NUMBER OF TRIANGLES FORMED BY DIAGONALS FROM ONE VERTEX 4 SIDES = 2 TRIANGLES
INTERIOR ANGLE SUM FIND THE NUMBER OF TRIANGLES FORMED BY DIAGONALS FROM ONE VERTEX 8 SIDES = 6 TRIANGLES
INTERIOR ANGLE SUM EACH TRIANGLE HAS 180 DEGREES IF N IS THE NUMBER OF SIDES THEN: (N – 2 ) 180 = INT ANGLE SUM
2 3 1 4 5 INT ANGLE SUM = ( 5 – 2 ) 180 ( 3 ) 180 = 540 DEGREES
REGULAR POLYGONS REGULAR POLYGONS HAVE EQUAL SIDES AND EQUAL ANGLES SO WE CAN FIND THE MEASURE OF EACH INTERIOR ANGLE
EACH INTERIOR ANGLE OF A REGULAR POLYGON = (N – 2 ) 180 N REMEMBER N = NUMBER OF SIDES
REGULAR HEXAGON INT ANGLE SUM = (6 – 2 ) 180 =720 EACH INT ANGLE = 720 = 120 6
EXTERIOR ANGLE SUM EXTERIOR ANGLE THE MEASURE OF EACH EXTERIOR ANGLE OF A REGULAR POLYGON IS 360 N ALL POLYGONS HAVE AN EXTERIOR ANGLE SUM OF 360