Area of Plane Shapes

	Triangle Area = ½b×h b = base h = vertical height		Square Area = a² a = length of side
	Rectangle Area = b×h b = breadth h = height		Parallelogram Area = b×h b = breadth h = height
	Trapezium Area = ½(a+b)h h = vertical height		Circle Area = πr² Circumference=2πr r = radius
	Ellipse Area = πab Perimeter=π(a+b)		Sector Area = ½r²θ r = radius θ = angle in radians