The triangle shaped entrance to the cavern i 1 1/2 feet tall and 4 feet wide whats the area

A=1/2 b*h
So substitute it in 1/2*1/2*4
1/2*1/2= 1/4
1/4*4= 4/4= 1 so the entrance is 1 foot tall

When an individual specializes to produce one good, and then acquires additional desired goods from other specialists

A) both parties gain as a result of voluntary exchange.
B) both parties gain as a result of fraudulent exchange.
C) neither party gains as specialization decreases efficiency.
D) neither party gains as specialization decreases productivity.