Explanation:
well, I see one large rectangle (20×6), and 2 small triangles with their horizontal sides being (20-8-6)/2 = 3 m. and their vertical joined side being 10-6 = 4 m.
the total area is simply the sum of the rectangle and the 2 triangles.
the rectangle is
20×6 = 120 m²
each triangle is
4×3/2 = 2×3 = 6 m²
we have 2 of them, so their combined area is 2×6 = 12 m².
the total area is
120 + 12 = 132 m²