Formulas needed:
Square area = b^2
Rectangle area = bh
Triangle area = bh/2
Parallelogram = bh
Trapezoid area = a+b/2(h)
Rhombus area = pq/2
Even better; use online calculators.
To use these formulas, you need to substitute the values given for b,h,a,b,p or/and q and then solve to get area.
So for this example, since it's a rectangle, you use formula A = bh. Base is 5.1, and height is 6.
Substitute now.
A = bh
= (5.1)(6) (substitute)
= 30.6 (multiply)
Therefore the area is 30.6 m^2. Don't forget the unit measurements, which is *measurement*^2.