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.
O is the center of the circle in the figure below.
What is its circumference?
Look at the circle in the figure:
Its radius is equal to 4.
What is its circumference?
Look at the circle in the figure:
The radius is equal to 7.
What is the area of the circle?
Given that the diameter of the circle is 7 cm
What is the area?
O is the center of the circle in the diagram below.
What is its area?
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
Look at the circle in the figure.
What is its circumference if its radius is equal to 6?
Look at the circle in the figure:
The diameter of the circle is 13.
What is its area?
Look at the circle in the diagram.
AB is a chord.
Is it possible to calculate the area of the circle?
A circle has an area of 25 cm².
What is its radius?
Is it possible that the circumference of a circle is 8 meters and its diameter is 4 meters?
Look at the circle in the figure.
What is its circumference if its radius is equal to 6?
Formula of the circumference:
We insert the given data into the formula:
Look at the circle in the figure:
The diameter of the circle is 13.
What is its area?
First, let's remember what the formula for the area of a circle is:
The problem gives us the diameter, and we know that the radius is half of the diameter therefore:
We replace in the formula and solve:
42.25π
Look at the circle in the diagram.
AB is a chord.
Is it possible to calculate the area of the circle?
Since AB is just a chord and we know nothing else about the diameter or the radius, we cannot calculate the area of the circle.
It is not possible.
A circle has an area of 25 cm².
What is its radius?
Area of the circle:
We insert the known data:
Divide by Pi:
Extract the root:
cm
Is it possible that the circumference of a circle is 8 meters and its diameter is 4 meters?
To calculate, we will use the formula:
Pi is the ratio between the circumference of the circle and the diameter of the circle.
The diameter is equal to 2 radii.
Let's substitute the given data into the formula:
Therefore, this situation is not possible.
Impossible
Given the semicircle:
What is the area?
A circle has a circumference of 31.41.
What is its radius?
A circle has a circumference of 50.25.
What is its radius?
The circumference of a circle is 14.
How long is the circle's radius?
Below is a circle bounded by a parallelogram:
All meeting points are tangential to the circle.
The circumference is 25.13.
What is the area of the parallelogram?
Given the semicircle:
What is the area?
Formula for the area of a circle:
We complete the shape into a full circle and notice that 14 is the diameter.
A diameter is equal to 2 radii, so:
We replace in the formula:
24.5π
A circle has a circumference of 31.41.
What is its radius?
To solve the exercise, first we must remember the circumference formula:
P is the circumference and Pi has a value of 3.14 (approximately).
We substitute in the known data:
Keep in mind that the result can be easily simplified using Pi:
Finally, we simplify by 2:
5
A circle has a circumference of 50.25.
What is its radius?
We use the formula:
We insert the known data into the formula:
8
The circumference of a circle is 14.
How long is the circle's radius?
We begin by using the formula:
We then insert the given data into the formula:
Lastly we divide Pi by 2:
Below is a circle bounded by a parallelogram:
All meeting points are tangential to the circle.
The circumference is 25.13.
What is the area of the parallelogram?
First, we add letters as reference points:
Let's observe points A and B.
We know that two tangent lines to a circle that start from the same point are parallel to each other.
Therefore:
And from here we can calculate:
Now we need the height of the parallelogram.
We know that F is tangent to the circle, so the diameter that comes out of point F will also be the height of the parallelogram.
It is also known that the diameter is equal to two radii.
Since the circumference is 25.13.
Circumference formula:
We replace and solve:
The height of the parallelogram is equal to two radii, that is, 8.
And from here you can calculate with a parallelogram area formula: