SECTION 1.4SURFACE AREAS OF OTHERCOMPOSITE SOLIDS
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REVIEW: AREAS OF TRIANGLES AND CIRCLES
Area of a Triangle – Base times Height divided by 2
The base and height must be perpendicular
Area of a Circle = x r x r
= 3.14159162
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SURFACE AREA OF CYLINDERS & TRIANGULAR PRISMS
The base of a cylinder is a circle
The surface area of a cylinder is the areaof all the sides
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PRACTICE FIND THE SURFACE OF THE FOLLOWING SOLIDS:
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SURFACE AREAS OF COMPOSITE SOLIDS
A composite solid is a shape with two or solids combined
Two methods for finding the surface area of a compositesolid
1st Method:
Draw the faces of all six sides
Find the area of each side, then find the sum
2nd Method:
Find the surface area of each solid
Subtract the areas that are covered
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EX: FIND THE SURFACE AREA OF THE GIVEN SOLID
Cut the solid into two piecesand draw the sides
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Place the circle on top of the
rectangle to get a complete side
shaded
Add all the sides up to find thesurface area of the solid
PRACTICE: FIND THE SURFACE AREA OF THE SOLID
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Find the area of eachrectangular prism
Then subtract all the sidesthat are covered!
HOMEWORK:
P40, 41 #3, 4, 5, 8, 9
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AREA OF A CIRCLE:
To find the area of a circle, cut it into 8 equal pieces
Put the pieces together to create a parallelogram
The length of the top is equal to half the perimeter
The height is equal to the radius of the circle
