There are an infinite number of points on the circumference of a circle and an infinite number of points on a semi-circle so the answer to your question is "An infinite number of pairs of points."
Measure the distance between the two end points!
Measure the perimeter of the wheel using a tape measure. Then use the formula to find out the diameter D = perimeter/3.14 ========================================== You could certainly do it that way. But it would be much more direct to just measure all the way across the wheel, between the two points on the edge of the wheel that are furthest apart. That would be the diameter.
the measure of a straight-line distance between two points is called length.
circumference/pi Divide the area by Pi (3.1415926535...). Take the square root of the result and multiply it by 2. Measure the distance between 2 opposite points
One measure of distance between them.
Measure the distance between the two end points!
I guess 3 . Take these 3 points 2 at a time . These two points would be the diameter of the circle .
Measure the perimeter of the wheel using a tape measure. Then use the formula to find out the diameter D = perimeter/3.14 ========================================== You could certainly do it that way. But it would be much more direct to just measure all the way across the wheel, between the two points on the edge of the wheel that are furthest apart. That would be the diameter.
Calipers are for measuring diameter of rounded objects. For instance you measure a ball, then carefully not changing the measurement pull the caliper off the ball and measure the gap between it's points with a ruler.
the measure of a straight-line distance between two points is called length.
circumference/pi Divide the area by Pi (3.1415926535...). Take the square root of the result and multiply it by 2. Measure the distance between 2 opposite points
Small circles
No. The circles are circles. The poles are points. If the circles were points, then they might be called the Arctic and Antarctic Poles, but they wouldn't be called the Arctic and Antarctic Circles since they would be only points.
One measure of distance between them.
The radius of a circle is the distance from the center of the circle to any point on its circumference. If the radius of a circle is given as 26.4 cm, then that means the distance from the center to the edge of the circle is 26.4 cm. This measurement is constant for any point on the circle, as all points on the circumference are equidistant from the center.
The curve between two points is known as an arc. Arcs and circles are used extensively in geometry. They are used in the real world by engineers and digital artists.
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