I found the accompanying image of this problem. The triangle is a right triangle.
area of a right triangle = ab/2 where: a and b are the legs
based on the image: a = 5 m
20 square meters = (5m * b) /2
20 sq. m * 2 = 5m * b
40 sq. m / 5m = b
8 m = b
So the image consists of 2 right triangles with a square in the middle.
Area of a square = a² = (8m)² = 64m²
Total area of the parallelogram = 2 right triangle * 20m² + 1 square *64m²
Total Area = 40m² + 64m²
Total area = 104m² ⇒ 104 square meters.