GEOMETRY

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MGF1106
Unit Three Ex. 5.10 Formulas Applicable For
Computing Measurements Of Geometric
Figures Objective 41
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Ex. 5.10
Objective 41
To find the perimeter, area, or volume of a
geometric figure that requires a combination of
geometric formulas
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Study the figure showing a regular polygon. Then
determine the formula for computing the total
area of the pentagon.
Step 1 Find area of triangle.
h
b
4
Step 2 How many of these triangles are
contained in the figure?
5
Step 3 Multiply the area of the triangle by 5.
5
Find the perimeter of a window which has the
shape of a rectangle surmounted by an equilateral
triangle.
x
x
P x x y x y
y
y
P 3x 2y
x
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Find the area of the figure shown below.
Step 1 Find the area of the triangle.
Step 2 Find the area of the rectangle.
A xy
A bh
Step 3 Find the total area.
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Find the volume of an oil can that has the shape
of cylinder surmounted by a hemisphere.
Step 1 Find the volume of the hemisphere.
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Step 2 Find the volume of the cylinder.
V ? r2h
Step 3 Add the volume of the hemisphere to the
volume of the cylinder.
9
Study the figure below to determine the formula
for the total surface area, A.
1. Find the area of the triangle.
A yh
2. Find the area of the rectangle.
A bh
A 2y(5x)
10xy
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3. Find the area of each semicircle.

4. Find the total area by adding the areas
found in 1, 2 and 3.