Answer:
180 cm²
Step-by-step explanation:
From inspection of the diagram, the surface area is made up of the area of 4 congruent triangles and the area of one square.
Area of a square = x² (where x is the length of one side)
⇒ area of the square = 6² = 36 cm²
Area of a triangle = 1/2 x base x height
⇒ area of one triangle = 1/2 x 6 x 12 = 36 cm²
Total surface area = 4 x area of one triangle + area of the square
= 4 x 36 + 36
= 144 + 36
= 180 cm²
