- (3) The length of the arc MP is equal to aã₤ö¡ã₤cotã₤ö¡; and the value of this for the given angle is ôñ8751. This is as much as to say that the curved partition-wall which we are considering is shorter than a radial partition in the proportion of 8ôƒ to 10, or seven-eights almost exactly.
But we must