This question is not easy to answer and even more complicated to understand. If you imagine any point on a flat surface and a series of points whose distance from that point is identical, then you are looking at a circle.
![B - What is circumference](/_ipx/f_png,s_500x479/https://cdn.tutorela.com/images/B_-_What_is_circumference.width-500.png)
This question is not easy to answer and even more complicated to understand. If you imagine any point on a flat surface and a series of points whose distance from that point is identical, then you are looking at a circle.
\( r=11 \)
Calculate the circumference.
The perimeter of any circumference can be calculated. Generally, we can say that to calculate it, we must multiply by the value of (pi) and the length of the radius.
Click to access the article on the perimeter of the circumference.
Another equally important data that we can obtain with respect to any circumference is the area of the circle. To find it, we must raise the length of the radius squared and then multiply the result obtained by π. Click here to access the article on the area of the circle.
\( r=7 \)
Calculate the circumference.
\( r=2 \)
Calculate the circumference.
\( r=6 \)
Calculate the circumference.
Let's consider the following circle.
The radius of the circle is equal to .
Use the image and the data provided to calculate:
1. the diameter of the circumference
2. the perimeter of the circle
3. the area of the circle
Solution:
The perimeter of the circumference equals .
3. To calculate the area of the space inside the circumference, i.e., the circle, we must square the length of the radius of the circumference and then multiply the result obtained by the value of .
Thus, we obtain:
The area of the circle is
Answer:
The diameter of the circle equals .
Let's consider the following circle.
We know that its diameter is .
Use the image and the data provided to calculate:
Solution:
We obtain that:
The perimeter of the circumference is .To calculate the area of the circle, we must raise the length of the radius (obtained in a. above) of the circumference to the square and then multiply the result obtained by the value of .
Thus, we obtain:
A circle has a radius of 3 cm.
What is its perimeter?
O is the center of the circle in the diagram.
What is its perimeter?
O is the center of the circle in the figure below.
What is its circumference?
Assignment:
Given the circumference of the figure
The diameter of the circle is ,
Solution
It is known that the diameter of the circle is twice its radius, i.e. it is possible to know the radius of the circle in the figure.
Tofind the area of the circle, we replace the data we have in the formula for the calculation of the circle
We replace the data we have:
Answer
Request
Given an equilateral triangle in a circle
What is the areaof the circle?
Solution
Recall first the theorem that a circumferential angle that is inclined about the diameter is equal to 90 degrees.
That is, the triangle inside the circle is a right triangle and isosceles, so we can use the Pythagorean formula.
We replace the data we have with the Pythagorean formula
The root cancels the power and therefore we obtain that
That is
The root of is and therefore the diameter is equal to and the radius is equal to half of the diameter and therefore it is equal to
Therefore we obtain that the diameter is equal to
And the radius is
Then we add the formula for the area of the circle
Answer
Calculate the area of a circle with a radius of 5 cm.
A circle has a radius of 3 cm.
What is its area?
A circle has a radius of 6 cm.
What is its area?
Given the semicircle:
Consigna
Calculate its area
Solution
Since we know that it is a semicircle we can conclude that the base of the semicircle is the diameter.
We know that the diameter is twice the radius and therefore we can know the radius of the circle.
The formula for calculating the area of the circumference is
We replace the data in the formula
Since the formula was the area of the semicircle we divide the area of the circle by and get the answer.
Answer
Request
Given the circumference of the figure
Given that the radius is equal to ,
What is the circumference?
Solution
The radius of the circle is
We use the formula of the circumference
Replace by
We obtain
Answer
A circle has a radius of 8 cm.
Calculate the area of the circle.
A circle has a radius of 10 cm.
Calculate the area of the circle.
A circle has a diameter of 14 cm.
Calculate the area of the circle.
Request
Given the circumference of the figure.
Given that the radius is equal to ,
What is the circumference?
Solution
The radius of the circle
We use the formula of the circumference
Replace by
We obtain
Answer
Request
Given the circumference of the figure.
Given that the radius is equal to ,
What is the circumference?
Solution
Diameter of the circumference
We divide by
Therefore the radius of the circle is
We use the formula of the circumference
Replace by
We obtain
Answer
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The area of the circle equals \( 36\pi\text{.} \)
Calculate the circumference.
Look at the circle in the figure:
\( \)
The radius of the circle is 4.
What is its area?
\( r=11 \)
Calculate the circumference.
O is the center of the circle in the figure below.
What is its circumference?
We use the formula:
We replace the data in the formula:
cm
Look at the circle in the figure:
Its radius is equal to 4.
What is its circumference?
The formula for the circumference is equal to:
8π
Look at the circle in the figure:
The radius is equal to 7.
What is the area of the circle?
Remember that the formula for the area of a circle is
πR²
We replace the data we know:
π7²
π49
49π
Given that the diameter of the circle is 7 cm
What is the area?
First we need the formula for the area of a circle:
In the question, we are given the diameter of the circle, but we still need the radius.
It is known that the radius is actually half of the diameter, therefore:
We substitute the value into the formula.
cm².
O is the center of the circle in the diagram below.
What is its area?
Remember that the formula for the area of a circle is
πR²
We insert the known data:
π3²
π9
cm²