Well, drawing out the diagram; you should have one triangle with all 3 sides with values. Lets call the radius 'r' , the chord length 'c' and the arc length 'a'. Your triangle should have two sides labelled each as 'r', and 'c'should be the last side.
Firstly, we know that the rule for the arc length is radius x theta (radians).
So we need a theta. To find theta, we can use the cosine rule, since we have all 3 sides and no angle.
The cosine rule is a^2=b^2+c^2-2bcCosA. We can transpose this into: CosA=(b^2+c^2-a^2)/2bc.
If we sub in our 'c' as the 'a' in the rule above and the two 'r's as 'b' and 'c', we get our new rule as CosC=(r^2+r^2-c^2)/2rr. We can then simplify that to be CosC = (2r^2-c^2)/2r^2. After that, inverse cosine the value and you should get angle C.
Finally sub in your values into the arc length rule: radius x theta, and you should get your answer.
P.S. Make sure your calculator is in radians.
you have a triangle formed by the radius on 2 and the chord on the other. the angle in that triangle that is opposite the chord, find its measure in radians take that measure (in radians) and multiply it by the radius to get the arc length
If the central angle is 70 and the radius is 8cm, how do you find out the chord lenght?
Unless the chord is the diameter, there is no way to measure the radius of the circle. This is because the radius is in no way dependent on chord length since circles have infinite amount of chord lengths.
If the radius is 8cm and the central angle is 70, how do yu workout the chord lenght?
The longest chord in a circle is its diameter and halve of this is its radius.
you have a triangle formed by the radius on 2 and the chord on the other. the angle in that triangle that is opposite the chord, find its measure in radians take that measure (in radians) and multiply it by the radius to get the arc length
multiply the chord length and radius and divide by 2
If you are given a chord length of a circle, unless you are given more information about the chord, you can not determine what the radius of the circle will be. This is because the chord length in a circle can vary from a length of (essentially) 0, up to a length of double the radius (the diameter). The best you can say about the radius if given the chord length, is that the length of the radius is at least as long has half half the chord length.
If the central angle is 70 and the radius is 8cm, how do you find out the chord lenght?
Unless the chord is the diameter, there is no way to measure the radius of the circle. This is because the radius is in no way dependent on chord length since circles have infinite amount of chord lengths.
If the radius is 8cm and the central angle is 70, how do yu workout the chord lenght?
The longest chord in a circle is its diameter and halve of this is its radius.
Assume that the height of the segment is h, the chord length is c and the radius is r then: r2=(r-h)2+(c/2)2 (We join two radii to the two ends of the chord then extend the height of the segment to the center of the circle in which the segment is inscribed so this height will bisect the chord and you use the pythagorean theorem to find the radius)
r = known radius x = known arc length --------------------------- C (circumference of circle) = 2 * PI * r A (angle of chord in degrees) = x / C * 360 L (length of chord) = r * sin(A/2) * 2
You cannot.
The length of a chord = pi*r*x/180 where x is the angle subtended. = pi*5*80/180 = 6.98 cm
Imagine if you will a circle with a chord drawn through it and a line running from the center of that chord to the center of the circle. That line is necessarily perpendicular to the chord. This means you have a right triangle whose hypotenuse is the radius of the circle. The radius is thus given by: r = sqrt{(1/2 chord length)^2 + (length of perpendicular line)^2} The actual formula to find the radius is as follows: r= C squared/8a + a/2, where C is the chord length, and a is the distance from center point of the chord to the circle , and a and C form an angle of 90 degrees. the entire formula before simplification is r = sqrt {(1/2 C)^2 + (r-a)^2}