All SAT Math Resources
Example Questions
Example Question #11 : Prisms
The dimensions of a right rectangular prism are such that the second dimension is twice the length of the first and the third is twice the length of the second. If the volume of the prism is 216 cubic units, what is its surface area?
126 square units
189 square units
215 square units
None of the other answers
252 square units
252 square units
Based on our prompt, we can say that the prism has dimensions that can be represented as:
Dim1: x
Dim2: 2 * Dim1 = 2x
Dim3: 2 * Dim2 = 2 * 2x = 4x
More directly stated, therefore, our dimensions are: x, 2x, and 4x. Therefore, the volume is x * 2x * 4x = 216, which simplifies to 8x3 = 216 or x3 = 27. Solving for x, we find x = 3. Therefore, our dimensions are:
x = 3
2x = 6
4x = 12
Or: 3 x 6 x 12
Now, to find the surface area, we must consider that this means that our prism has sides of the following dimensions: 3 x 6, 6 x 12, and 3 x 12. Since each side has a "matching" side opposite it, we know that we have the following values for the areas of the faces:
2 * 3 * 6 = 36
2 * 6 * 12 = 144
2 * 3 * 12 = 72
The total surface area therefore equals: 36 + 144 + 72 = 252 square units.
Example Question #3 : How To Find The Surface Area Of A Prism
The area of a given object is 30,096 in2. What is the area of this object in ft2?
None of the other answers
209 ft2
2508 ft2
1254 ft2
1881 ft2
209 ft2
Converting squared units is not difficult, though you have to be careful not to make a simple mistake. It is tempting to think you can merely divide the initial value (30,096) by 12, as though you were converting from inches to feet.
Begin by thinking this through as follows. In the case of a single dimension, we know that:
1 ft = 12 in or 1 in = (1/12) ft
Now, think the case of a square with dimensions 1 ft x 1 ft. This square has the following dimensions in inches: 12 in x 12 in. The area is therefore 12 * 12 = 144 in2. This holds for all two-dimensional conversions. Therefore, the two dimensional conversion equation is:
1 ft2 = 144 in2 or 1 in2 = (1/144) ft2
Based on this, we can convert our value 30,096 in2 thus: 30,096/144 = 209 ft2.
Example Question #4 : How To Find The Surface Area Of A Prism
The area of a given object is 24 yd2. What is the area of this object in in2?
20,736 in2
None of the other answers
10,368 in2
31,104 in2
864 in2
31,104 in2
Converting squared units is not difficult, though you have to be careful not to make a simple mistake. It is tempting to think you can merely multiply the initial value (24) by 36, as though you were converting from yards to inches.
Begin by thinking this through as follows. In the case of a single dimension, we know that:
1 yd = 36 in
Now, think the case of a square with dimensions 1 yd x 1 yd. This square has the following dimensions in inches: 36 in x 36 in. The area is therefore 36 * 36 = 1296 in2. This holds for all two-dimensional conversions. Therefore, the two dimensional conversion equation is:
1 yd2 = 1296 in2
Based on this, we can convert our value 24 yd2 thus: 24 * 1296 = 31,104 in2.
Example Question #3 : How To Find The Surface Area Of A Prism
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 #84 : Solid 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 #21 : Prisms
The shaded face of the above rectangular prism is a square. In terms of , give the surface area of the prism.
Since the front face of the prism is a square, the common sidelength - and the missing dimension - is .
There are two faces (front and back) that are squares of sidelength ; the area of each is the square of this, or .
There are four faces (left, right, top, bottom) that are rectangles of dimensions 25 and ; the area of each is the product of the two, .
The surface area is the total of their areas:
Example Question #71 : Solid Geometry
The shaded face of the above rectangular prism is a square. In terms of , give the surface area of the prism.
Since the top face of the prism is a square, the common sidelength - and the missing dimension - is 25.
The surface area of a rectangular prism with length , width , and height can be found using the formula
.
Setting, and solving for :
Example Question #245 : Geometry
A rectangular box has a length of 2 meters, a width of 0.5 meters, and a height of 3.2 meters. How many cubes with a volume of one cubic centimeter could fit into this rectangular box?
3.2 x 102
3.2 x 10-3
3.2
3,2 x 103
3.2 x 106
3.2 x 106
In order to figure out how many cubic centimeters can fit into the box, we need to figure out the volume of the box in terms of cubic centimeters. However, the measurements of the box are given in meters. Therefore, we need to convert these measurements to centimeters and then determine the volume of the box.
There are 100 centimeters in one meter. This means that in order to convert from meters to centimeters, we must multiply by 100.
The length of the box is 2 meters, which is equal to 2 x 100, or 200, centimeters.
The width of the box is 0.5(100) = 50 centimeters.
The height of the box is 3.2(100) = 320 centimeters.
Now that all of our measurements are in centimeters, we can calculate the volume of the box in cubic centimeters. Remember that the volume of a rectangular box (or prism) is equal to the product of the length, width, and height.
V = length x width x height
V = (200 cm)(50 cm)(320 cm) = 3,200,000 cm3
To rewrite this in scientific notation, we must move the decimal six places to the left.
V = 3.2 x 106 cm3
The answer is 3.2 x 106.
Example Question #2 : Prisms
A rectangular prism has a length that is twice as long as its width, and a width that is twice as long as its height. If the surface area of the prism is 252 square units, what is the volume, in cubic units, of the prism?
432
1728
27
216
108
216
Let l be the length, w be the width, and h be the height of the prism. We are told that the length is twice the width, and that the width is twice the height. We can set up the following two equations:
l = 2w
w = 2h
Next, we are told that the surface area is equal to 252 square units. Using the formula for the surface area of the rectangular prism, we can write the following equation:
surface area = 2lw + 2lh + 2wh = 252
We now have three equations and three unknowns. In order to solve for one of the variables, let's try to write w and l in terms of h. We know that w = 2h. Because l = 2w, we can write l as follows:
l = 2w = 2(2h) = 4h
Now, let's substitute w = 2h and l = 4h into the equation we wrote for surface area.
2(4h)(2h) + 2(4h)(h) + 2(2h)(h) = 252
Simplify each term.
16h2 + 8h2 + 4h2 = 252
Combine h2 terms.
28h2 = 252
Divide both sides by 28.
h2 = 9
Take the square root of both sides.
h = 3.
This means that h = 3. Because w = 2h, the width must be 6. And because l = 2w, the length must be 12.
Because we now know the length, width, and height, we can find the volume of the prism, which is what the question ultimately requires us to find.
volume of a prism = l • w • h
volume = 12(6)(3)
= 216 cubic units
The answer is 216.
Example Question #1 : Finding Volume Of A Rectangular Prism
The dimensions of Treasure Chest A are 39” x 18”. The dimensions of Treasure Chest B are 16” x 45”. Both are 11” high. Which of the following statements is correct?
There is insufficient data to make a comparison between Treasure Chest A and Treasure Chest B.
Treasure Chest A has the same surface area as Treasure Chest B.
Treasure Chest B can hold more treasure.
Treasure Chest A can hold more treasure.
Treasure Chest A and B can hold the same amount of treasure.
Treasure Chest B can hold more treasure.
The volume of B is 7920 in3. The volume of A is 7722 in3. Treasure Chest B can hold more treasure.