All SAT II Math I Resources
Example Questions
Example Question #771 : Geometry
The radius of the base of a cone is ; its slant height is two-thirds of the diameter of that base. Give its surface area in terms of .
The formula for the surface area of a cone with base of radius and slant height is
.
The diameter of the base is twice radius , or , and its slant height is two-thirds of this diameter, which is . Substitute this for in the formula:
Example Question #2 : How To Find The Surface Area Of A Cone
The radius of the base of a cone is ; its height is twice of the diameter of that base. Give its surface area in terms of .
The formula for the surface area of a cone with base of radius and slant height is
.
The base has radius and diameter . The height is twice the diamter, which is . Its slant height can be calculated using the Pythagorean Theorem:
Substitute for in the surface area formula:
Example Question #16 : Solid Geometry
The height of a cone is ; the diameter of its base is twice the height. Give its surface area in terms of .
The formula for the surface area of a cone with base of radius and slant height is
.
The diameter of the base is twice the height, which is ; the radius is half this, which is .
The slant height can be calculated using the Pythagorean Theorem:
Substitute for and for in the surface area formula:
Example Question #123 : Geometry
The circumference of the base of a cone is 80; the slant height of the cone is equal to twice the diameter of the base. Give the surface area of the cone (nearest whole number).
The formula for the surface area of a cone with base of radius and slant height is
.
The slant height is twice the diameter, or, equivalently, four times the radius, so
and
The radius of the base is the circumference divided by , which is
Substitute:
Example Question #2 : How To Find The Surface Area Of A Cone
The circumference of the base of a cone is 100; the height of the cone is equal to the diameter of the base. Give the surface area of the cone (nearest whole number).
The formula for the surface area of a cone with base of radius and slant height is
.
The diameter of the base is the circumference divided by , which is
This is also the height .
The radius is half this, or
The slant height can be found by way of the Pythagorean Theorem:
Substitute in the surface area formula:
Example Question #21 : Surface Area
If a cone were unfurled into a 2-dimensional figure. The lateral area of the cone would look most like which figure?
Rectangle
Sector of a Circle
Triangle
Circle
Sector of a Circle
When creating a net image of a 3D figure - one imagines it is made of paper and is unfurled into its' 2D form. The lateral portion of the cone cone would be unfurled into the image of a Sector of a Circle. To include the full surface area of the cone a circle is included to form the base of the cone as in the figure below. The lateral area portion is the top part of the figure below.
Example Question #22 : Surface Area
Find the surface area of a cube with side length of 6in.
A cube is made up of 6 identical sides. Find the area of one side and multiplying it by 6 will result in the surface area of a cube.
a is the side length, in this case 6in.
Example Question #27 : Surface Area
What is the surface area of a cylinder with height 10 and radius 7?
The formula of the surface area of a cylinder is:
In this problem h is 10 and r is 7. Substituting in those values gives us:
Simplifying and combining the like terms results in:
Example Question #28 : Surface Area
Figure not drawn to scale.
Find the surface area of the box above.
Surface area: 48 yd2
Surface area: 84 yd2
Surface area: 82 yd3
Surface area: 84 yd3
Surface area: 82 yd2
Surface area: 82 yd2
You can find the surface area of a box by following the equation below:
The surface area of the box is 82yd2 (remember that area measurements are square units NOT cubic units)
Example Question #29 : Surface Area
The shaded face of the provided rectangular prism is a square. If the surface area of the prism is , give in terms of .
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 :