Areas

The area of a rectangle is calculated by multiplying its length by its breadth (A = l * b).
For a square, since all sides are equal, the area is found by squaring the length of one side (A = s^2).
The area of a triangle is half the product of its base and its height (A = 0.5 * b * h).
In the case of a parallelogram, the area is also the product of its base and height (A = b * h).
The area of a trapezium is the mean (average) of the lengths of the two parallel sides multiplied by the height (A = 0.5 * (a + b) * h).
For a circle, the area is calculated using the formula A = πr^2, where r is the radius of the circle.
Composite shapes (shapes made up of more than one shape) can have their areas found by adding or subtracting the areas of the individual shapes.
The total surface area of a prism can be found by calculating the area of each face and then adding these together.
The surface area of a cylinder is found by calculating the area of its two circular ends and the area of its curved surface, which is equal to the product of the circumference of one of its ends and its height.
Similarly, the surface area of a cone can be calculated by adding the area of its circular base and that of its curved surface, which is equal to the product of π, the radius of the base, and the slant height of the cone.
The area of a sector of a circle (a ‘slice’ of the circle) can be found by finding the fraction of the whole circle that the sector represents, and multiplying this by the total area of the circle.