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Example Questions
Example Question #242 : Geometry
Angie is painting a 2 foot cube for a play she is in. She needs of paint for every square foot she paints. How much paint does she need?
It is impossible to convert between metric units and feet.
None of the available answers
First we must calculate the surface area of the cube. We know that there are six surfaces and each surface has the same area:
Now we will determine the amount of paint needed
Example Question #621 : Geometry
What is the surface area of an equilateral triangluar prism with edges of 6 in and a height of 12 in?
Let and .
The surface area of the prism can be broken into three rectangular sides and two equilateral triangular bases.
The area of the sides is given by: , so for all three sides we get .
The equilateral triangle is also an equiangular triangle by definition, so the base has congruent sides of 6 in and three angles of 60 degrees. We use a special right traingle to figure out the height of the triangle: 30 - 60 - 90. The height is the side opposite the 60 degree angle, so it becomes or 5.196.
The area for a triangle is given by and since we need two of them we get .
Therefore the total surface area is .
Example Question #1 : How To Find The Surface Area Of A Prism
What is the total surface area of a box without a lid, if the dimensions of the base of the box are , and the box is tall?
The surface area of a rectangular prism is . Our prism, however, is missing its top, so it will be . This gives us .
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