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Chapter 9 and 10 Journal. Marcela Janssen. areas. Areas. Trapezoid (base1 x base2)h 2 Kite (½ diagonal2) diagonal 1 Rhombus (½ diagonal2) diagonal 1 Any polygon with any # of sides Area = (½ sa ) n. Square base x height Rectangle base x height
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Chapter 9 and 10Journal Marcela Janssen
Areas • Trapezoid(base1 x base2)h 2 • Kite(½ diagonal2) diagonal 1 • Rhombus (½ diagonal2) diagonal 1 • Anypolygonwithany # of sidesArea = (½ sa) n • Squarebase x height • Rectanglebase x height • Trianglebase x height 2 • Parallelogrambase x height
Examples Area 9m 9m x 3m 27m2 3m 6mm 6mm x 4mm 4mm 2 24/2 = 12mm2
Composite figures Composite Figure: A plane figure made up of triangles, rectangles, trapezoids, circles, orother simple shapesor a three dimensional-figure made up of prisms, cones, pyramids, cylinders and other simple three-dimensional figures. Plane figure Tridimensional composite figure
Tofindthearea of a composite figure: • Divide tha figure into simple shapes • Findtheareas of the simple shapes • Addall of theareas of the simple shapestogetthearea of thewholecomposite figure
Example 6cm Ill 7 cm 1 cm 2 cm 12 cm (10 x 6)2 2 120 2 60 cm 12x 2 24 60 + 24 84 cm 2
Areas of Circles • Tofindthearea of a circlejust use theequation: Area = π r 2
Solids A solidis a three-dimensional figure. Sphere Triangular prism Rectangular ppyramid
Prisms Prism: isformedby 2 ll congruentpolygonal faces called bases by faces that are parallelogram. Differencebewteen a prism and a pyramid:
Tofindthesurfacearea of a prism: Surface Area = (perimeter of base) L + 2(Area of base) Example: Surface A. = (16m) 7 + 2(24m2) 112 + 48 160 m2
A net is a diagram of thesurfaces of a tridimensiitionalobject,
Cylinders Isformedbytwoparallelcongruent circular bases and a curvedsurfacethatconnectsthe bases. Tofindthesurfacearea: SurfaceArea = 2(π r 2) + (2π r)h
AREA OF PYRAMID NOT EXAMPLES
Pyramid Tofindthe total surfacearea: ½ pl + b L= lenght of the lateral face A= area of the base P= perimeteropfthe base
AREA OF CONE NOT EXAMPLES
Cone Tofindthesurfacearea of a cone: π r√r2 +h2 R= radius H = height
Cube A cube is a squareprismwith 6 congruent faces. Tofindthesurfacearea: 6 a 2 A = lenght of edges
Example 1 Surface Area = 6(5 in)2 = 6(25) = 150 in2
Example 2 Given that the height of a cube is 5 ft 3 in what is the surface area that it has? Surface Area = 6(5 ft 3 in)2 = 6(63 in) = 6(63) = 378 in2 = 31.5 ft2
Example 3 Howmuchisthesurfacearea of thisrubiks cube? Surface Area = 6(8 in)2 = 6(64) = 384 in2
Cavalieri’sPrinciple • Iftwothree-dimensional figures havethesame base area, and sameheight, theywillhavethesamevolume.
Volume • Prism • Cylinder πr2 • Pyramid 1/3 bh Cone 1/3 π r2 h
Spheres Sphere: A tridimensional solidcreatedbyallpointsequidistant (radius) fromthe center point. Hemisphere: Half of a sphere Great Circle: Any line drawnaroudthespherethatcutsitintotwohemisphere (equator)
Surfacearea of a sphere: 4 π r2 Example: r= 8.5 4π 8.52 4π 17 Volume of a sphere: 4/3 πr3 How many water is needed to fill this sphere with water with a radius of 8.5? 4/3 πr3 4/3 π 8.53 86 mm
TO BE GRADED: • SPHERES • PRISMS • AREA OF A CUBE