Area of right triangle with hypotenuse H is A=(1/4)H^2sin(2theta) where theta is one of the acute angles. Use differentials to estimate the relative errors of the area A if H=4cm and theta is measured to be 30 degrees with an error of measurement of 15 minutes of arc. note: a minute of arc, 1' is approximately equal to (1/60) of a degree. I'm not quite sure what a measurement of arc is and whether i'm supposed to find the derivative or what? Im so lost, thanks in advance.