It says calculate in degrees, the angle subtended at the centre of a circleof radius 2.7 cm by anarc of length 6.9 cm
First of all you must realize that on a circle of fixed radius, the length of an arc is proportional to the angle that subtends it.
For example, to a 90 degree angle corresponds 1/4 of a circumference, to 180 degrees 1/2 the circumference. Double the angle, double the arc length.
Once this is understood you can say that
arc length = k*angle where k is the constant of proportionality or
l=k*a or k=l/a
Similarly
2*Pi*R=k*360 degrees or k=(2PiR)/360
It is the same k for the same circle
So
k=l/a=(2Pi*R)/360
You have a proportion l/a=(2Pi*R) /360
Knowing l an R you can isolate a
a= (180/Pi)*(l/R)
Your angle is
a=(180/Pi)*(6.9/2.7)=146.42 degrees
Now, you should note that the ratio 180 deg/Pi=57.29 is the value in degrees of an angle of 1 radian.
About 146 and a half degrees.
If this is homework, be sure to show your work.
SOURCE: finding the length of a triangle
might try
(54tan)/45
I don't have a calc that will do it or I would try it and see.
SOURCE: given a length of 30 cm on the x axis and a length
Yes, there is shortcut because this is right triangle, so you can use Pythagorean theorem (see picture).
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SOURCE: Error when using inverse trig inever used to get
If you are trying to calculate arcsine (sin^-1) and arccosine (cos^-1) the only whole number you can use are -1,0 and 1. This due to the fact that the domain of these functions is the closed interval [-1,1]. Any value outside that interval will trigger an error message. No limitation on the argument of the arc tangent or arc cotangent functions
If the angle unit is set to degree the arc will be in degrees, and if angle unit is radian, the arc will be in radians.
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