Area and Circumference of a Circle
Aligned To Common Core Standard:
Grade 7 Geometry - 7.G.B.4
How to Determine the Area and Circumference of a Circle? We have studied about the circle and have defined its various parts in detail. However, studying these parts is easier than solving the problems related to the circle. But don't worry, we are here to help you out in solving these problems. One common geometric problem related to the circle is finding area and circumference. Circumference and area are often confused as the same thing. The circumference is the enclosing boundary of the circle, while area is the space occupied by the circle. However, both share some common factors. Radius - Radius is the distance from the center of the circle to any point on its circumference. Calculating area or circumference requires us to know the radius of the circle. Pi - Pi (π) is defined as the ratio of circumference to the circle's diameter. But don't worry, you don't need to calculate it. It is a constant value and won't take more than twice to learn it by heart. The value of pi is 3.14 CALCULATING CIRCUMFERENCE - Circumference of a circle is denoted by 'c' and is twice its radius into the constant pi. To mathematically express it: C= 2 (π) r Taking r=4 inches and π=3.14 C= 2 * 3.14 *4 C= 25.12 inches CALCULATING AREA - The area of a circle is equal to squared radius times constant pi (π). You can find the area of a circle using the following equation: A = πr2 , Taking r=3 inches and π= 3.14 A = 3.14 *(3)2, A= 3.14 *3*3, A= 28.26 inches
Printable Worksheets And Lessons
- What Size Tablecloth
Step-by-step Lesson- I don't think I ever caught myself doing
this before, but I'm sure people do all the time.
- Guided Lesson
- The circle inside the square is a fundamental concept for kids
to grasp. Number 2 is a bit tricky.
- Guided Lesson Explanation
- If you look at problem number 2 like a twinky, don't forget about
- Practice Worksheet
- I take the visualization out of these problems to make sure students
are well rounded in their problem skills.
- Circumference of
a Circle Five Worksheet Pack - Use the chords, radius, and diameter
to find the circumferences of these circles.
- Matching Worksheet - All units were removed to protect the innocent! No, I just like saying that.
You don't even want to hear how long it took me to think up things that were characteristically perfect circles.
- Homework 1 - Ryan made a mini round bed for his friend. He wants to put a bed sheet. If the bed is 10 feet in diameter, how many square feet of bedding will he need to buy to cover the bed? Use 3.14 for pi
- Homework 2 - Tia buys a CD. Then she calculated that it has a circumference of 120 cm. What is the CD’s diameter? Use 3.14 for pi.
- Homework 3 - Ryan bought 1kg of lemons. He didn’t find a basket to keep them in. So he put in a round vessel. If the diameter of the vessel is 32, what is the area and circumference of the round vessel?
I did give up a few times when writing these and just say that you are a circle.
- Practice 1 - Sara measured the bowl. Then she calculated that it has a circumference of 70 cm. What is the bowl's diameter?
- Practice 2 - If the diameter of a circle is 25, find the circumference of the circle?
- Practice 3 - Roy made a tasty burger. The diameter of the burger was 22 cm. What was the area of the burger?
Math Skill Quizzes
These are verbatim what you could expect to see on any assessment for this standard.