The area of a trapezoid is given by the formula
... A = (1/2)(b₁+b₂)h
where b₁ and b₂ are the lengths of the parallel bases and h is the perpendicular distance between them.
Your diagram shows b₁ = 6 m + 1 m = 7 m and b₂ = 5 m. (It does not matter which you call b₁ or b₂.) The diagram also shows h = 3 m, the distance between the bases. (A proper diagram would indicate the dashed line is at right angles to the bases.)
Using this information in the formula, you have
... A = (1/2)·(7m + 5m)·(3 m)
... = (1/2)·(12 m)·(3 m)
... = 18 m²
The area of this trapezoid is 18 square meters.
