Answer:
bh + L(S1 + S2 + h)
Step-by-step explanation:
b stands for the bottom edge of the base triangle
h is the height of the base triangle
L is the length of the prism
S1 and S2 are the two edges of the base triangle
bh is the combined area of the two triangular faces
L(S1 + S2 + h) is the area of the three rectangular side faces
