The area of the two triangular bases is
A = (4 mm)(6 mm) = 24 mm²
The perimeter of the triangular base is
P = 2(6.3 mm) + 4 mm = 16.6 mm
so the lateral area is
A = (16.6 mm)(8 mm) = 132.8 mm²
The total surface area is the sum of the base areas and the lateral area.
total area = 24 mm² + 132.8 mm² = 156.8 mm²
This value corresponds to selection ...
D) 156.8 mm²
