Step-by-step explanation:
Area of 4 triangles = 1/2 x base x height
[tex] =4 \times \frac{1}{2} \times 7 \times 5 \\ = 2 \times 7 \times 5 \\ = 14 \times 5 \\ = 70 {m}^{2} [/tex]
Area of middle square = Length x Width
[tex] = 7 \times 7 \\ = 49 {m}^{2} [/tex]
Surface Area = Area of 4 triangles + Area of middle square =
[tex]70 + 49 \\ = 139 {m}^{2} [/tex]
