Areas
Area calculations refer usually to rectangular and triangular shapes. If you need the trigonometric function for calculations click here.
There are different ways to calculate the area of the opposite figure. Try to minimise the amount of calculation. The figure could be divided in three distinct areas
a=10.31×5.63+
b=6.25×5.76+
c=10.39×4.79
or the whole rectangle minus the hole (d)
A =16.67×10.31-6.25×4.55.
As you can see the 2nd method is easier. Look at the shape and try to shorten the calculations.
If you know only the sides of a triangle then use the formula given in the figure below.
An area can usually be divided it in triangles (rectangles, parallelograms, trapeziums etc).
Parallelograms has opposite sides parallel and equal. Diagonals bisect the figure and opposite angles are equal..
The trapezium has one pair of opposite sides parallel.
(A regular trapezium is symmetrical about the perpendicular bisector of the parallel sides.)
An arc is a part of the circumference of a circle; a part proportional to the central angle.
If 360° corresponds to the full circumference. i.e. 2 r then for a central angle of (see opposite figure) the corresponding arc length will be b = /180 x r .
