There are a couple of different ways of finding the length of the chord of a circle. Probably the best is what is called the half angle formula.
It depends on what information you have: radius, diameter, lengths of tangents from a point outside the circle, length of chord and its distance from the centre, etc. Also, the term is circumference, not circumfrence.
The solution depends on the information supplied. Basically, you find the area of the sector containing the segment and then deduct the area of the triangle formed by the chord and the two radii enclosing the sector. If you are given the radius(r) of the circle and the height(h) then construct a radius that is perpendicular to and bisects the chord. This will create two congruent triangles which together form the main triangle. Using Pythagoras enables the half-chord length to be calculated as the hypotenuse is r and the height (also the length of the third side) is r-h. With this information the full chord length can be established and thus the area of the main triangle. Using sine or cosine methods enables the sector angle at the centre to be calculated and thus the sector area. Simple subtraction produces the area of the segment. If you are given the radius and the chord(c) length then the construction referred to above enables the height of the main triangle to be calculated and a similar process will generate the area of that triangle and the sector area. This, in turn, will enable the segment area to be determined.
you will need to know the angle subtended by the arc; arc length = radius x angle in radians
The area of a sector of a circle with radius 12 and arc length 10pi is: 188.5 square units.
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.
Length of chord (assuming that is what you want) = 2*r*sin(x/2) where x is the measure of the angle subtended at the centre.
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
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}
The radial length equals the chord length at a central angle of 60 degrees.
You can use the cosine rule and the three lengths of the triangle to find the central angle X, (in radians). Then the length of the arc is r*X units.