The answer is 18.9, i think, because there is a formula for finding the total surface area of such pyramids, but i used the simpler way of finding all the separate areas of each face using this information:
since the base area is 3.9 m2, we could just add that to the total at the end.
since the base edge is 1.5 m and the height is 4m, we could find the area of the face by doing (1.5 times 4)/2 which would give us 3m2.
Since there are 5 faces(pentagonal), we would multiply 3 times 5, and would get 15m total for all the triangle faces.
so to get the total surface area, you would add 15 + 3.9 (which was the base area) and get 18.9m2....
....;);) hope this helps