area of triangle = ½ x base x vertical height = ½ a b Sin C
area of parallelogram = base x vertical height
area of trapezium = average of parallel sizes x distance between them
area of circle = pi x r*2
area of sector = angle/360 x area of circle
length of arc = angle/360 x circumference
area of segment = find area of the sector you
make by joining sides of the chord to the centre.
then find area of triangle (½ base x height or ½ a b
sinC), and then subtract it from area of sector