All ISEE Upper Level Math Resources
Example Questions
Example Question #191 : Plane Geometry
Find the area of a circle with a diameter of 16in.
To find the area of a circle, we will use the following formula:
where r is the radius of the circle.
Now, we know the diameter is 16in. We also know the diameter is two times the radius. Therefore, the radius is 8in. So, we get
Example Question #51 : Circles
A circle has a diameter of 18cm. Find the area.
To find the area of a circle, we will use the following formula:
where r is the radius of the circle.
Now, we know the diameter of the circle is 18cm. We also know the diameter is two times the radius. Therefore, the radius is 9cm.
Knowing this, we can substitute into the formula. We get
Example Question #1 : Circumference Of A Circle
What is the circumference of a circle with a radius equal to ?
The circumference can be solved using the following equation:
Example Question #1 : Circumference Of A Circle
The radius of a circle is . Give the circumference of the circle in terms of .
The circumference can be calculated as , where is the radius of the circle.
Example Question #2 : How To Find Circumference
The area of a circle is . Give the circumference of the circle in terms of .
Let .
The area of a circle can be calculated as , where is the radius of the circle.
The circumference can be calculated as , where is the radius of the circle.
Example Question #2 : Circumference Of A Circle
What is the circumference of a circle with a radius of ?
The circumference can be solved using the following equation:
Where represents the radius. Therefore, when we substitute our radius in we get:
Example Question #1 : Know And Use The Formulas For The Area And Circumference Of A Circle: Ccss.Math.Content.7.G.B.4
The perimeter of a given rectangle is equal to the circumference of a given circle. The circle has radius inches; the width of the rectangle is inches. What is the length of the rectangle?
inches
inches
inches
inches
inches
inches
The circumference of a circle with radius inches is
inches.
The perimeter of the rectangle is therefore inches. To find its length, substitute and into the equation and solve for :
inches
Example Question #191 : Geometry
The area of the shaded region in the above diagram is . Give the circumference of the circle.
The shaded region is an sector; this represents
of the circle. The area of the region is therefore
,
where is the radius. Setting and solving for :
The circumference of a circle is its radius multiplied by , or
Example Question #1 : How To Find Circumference
A circle has a radius of 5 miles, what is its circumference?
A circle has a radius of 5 miles, what is its circumference?
To find circumference, use the following formula:
Where r is our radius.
Plug in 5 miles to get our answer:
Example Question #2 : How To Find Circumference
While mailing some very important letters, you decide to use your circular rubber stamp. If the stamp has a radius of 3.5 cm, what is the circumference of the stamping surface?
Cannot be determined from the information provided.
While mailing some very important letters, you decide to use your circular rubber stamp. If the stamp has a radius of 3.5 cm, what is the circumference of the stamping surface?
Find circumference via the following:
Where r is our radius, which is 3.5 cm.