Arc length is a fraction of circumference. Area of a sector is a fractions of the area of a circle. Both can be calculated using the angle at the centre and the diameter or radius. Practice circle ...

THIS work of Prof. Smith's has a “very practical purpose,” viz, “to present in simple and intelligible form a body of geometric doctrine, acquaintance with which may fairly be demanded of candidates ...

If you’ve dealt with reactance, you surely know the two equations for computing inductive and capacitive reactance. But unless you’ve really dug into it, you may only know the formula the way a school ...