Answer:
He needs to find the area of each lateral face plus the area of the base. The total surface area is 84.
Step-by-step explanation:
area of a triangle= b×h×1/2
therefore area of each triangle(lateral face)= 6×4×1/2= 12
12×4 because there are 4 triangles=48
then the area of the base= 6×6= 36
total surface area= 36+ 48=84
