Given pyramid with octagonal base. Image of the pyramid attached below:
We know the formula of Lateral Area of pyramid =
where p represent the perimeter of the octagonal base
and l represent the slant height of the pyramid.
109.9 =
Solve for p
p = 32.81 cm
Perimeter of octagonal base (all sides are same) = 8*s
where s represent the side of octagon
8s = 32.81
Solve for s
s = 4.1 cm
Side of the octagon = 4.1cm (option D)
The amount of cardboard needed to make a cuboid box of dimensions 8 inch, 3 inches and 3 inches is 114 sq. inches.
<h3>What is the surface area of cuboid?</h3>Let the three dimensions(height, length, width) be x, y,z units respectively.
The surface area of the cuboid is given by
For this case, tissue box is almost cuboid shaped.
Also, its dimensions are given being 8 inches, 3 inches and 3 inches.
Suppose we measure the amount of cardboard needed in terms of area, then, the amount of cardboard needed to make that box(without any whole, full cuboid) is equal to the area of its surface(either outer or inner if we assume 0 inches thickness of cardboard),
Thus, we get:
Amount of cardboard needed = surface area of cuboid box with dimensions 8 by 3 by 3 (in inches)
=
Thus, the amount of cardboard needed to make a cuboid box of dimensions 8 inch, 3 inches and 3 inches is 114 sq. inches.
Learn more about surface area of cuboid here:
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