Diameter of a Circle Diameter of a Circle In this unit we are going to learn about “Diameter of a Circle�. We will first learn about what a circle is. To understand it more clearly, if we look at the real life examples from our life, we say the bangle, coins of the currency which we use for shopping, wheel of your bicycle; all are the examples of the figures which are in the shape of the circle. Remember the difference between the sphere and the circle. A circle is a two dimension figure; on another hand we say that the sphere is a three dimension figure. Now we will discuss about the radius of the circle. There exists a point called centre of the circle, which we observe is at equal distance from all the points of the boundary of the circle. We call this point as the centre of the circle. Now we look at the radius of the circle. Radius is the distance between the centre and the boundary. It is same at all the points. When we draw a circle, it is always of a certain radii (radii is the singular form of the word radius), say 7 cm. Then we take a compass and then set its arc at the distance of 7 cm. For this we will Place the Know More About Standard Deviation Formula Math.Tutorvista.com
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compass at a point on the plane and then form the circle with the centre. The point at which we place the compass and form the circle is circle is called as centre of the circle. The line so drawn called the circle, is basically the boundary of the circle. This boundary is the perimeter of any circle. For any circle, the radius always remains same no matter from which point it has been measured and we say that the diameter is the sum of the two radii. Moreover, if we look at the diameter of the circle, we say that the diameter of the circle is always double of the radius of the circle. Thus if we are given the radius of the circle and we need to find the diameter of the same circle, we say: Diameter = 2 * radius We can also say that the Diameter is the longest chord of the circle. If we draw the Diameter of a Circle, we observe it is the straight line, passing through the centre of the circle. It is the longest chord and is formed by the joining of two radii. Thus we can say that the radius of the circle can be known if we know the diameter of the circle by simply dividing the diameter by 2. We write the formula as follows: If ‘d’ is the diameter of the circle and ‘r’ is the radius of the circle, then we say that R = d /2, thus the radius is half of the diameter. Once we know the radius of the circle, it will help us to find the area and the circumference of the circle. In a circle, the area is the total space covered by the circle in the two dimensions. Learn More :- Box And Whisker Plot
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To find the circumference, if we have the diameter, the formula is, Circumference = d * (22/7), Given : AB is a chord in a circle with centre O. OC ⊥ AB. To prove: The point C bisects the chord AB. Construction: Join OA and OB Proof: In triangles OAC and OBC, m∠OCA = m∠OCB = 90 (Given) OA = OB (Radii) OC = OC (common side) ∠OAC = ∠OBC (RHS) CA = CB (corresponding sides) The point C bisects the chord AB. Hence the theorem is proved.
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