Answer:
B. 15 square meters (for the triangles)
D. 25 square meters (for the square base)
Bonus: The total surface area would be 85 square meters.
Explanation:
The square base is easier to deduce here; simply square 5 to get 25 square meters for the base.
The triangles require some math, however. But it is relatively simple
(5 * 6)/2
30/2
15 square meters for the triangles.
For bonus, I'll find the total surface area.
5² + 4((5 * 6)/2)
First, square 5 to get 25.
25 + 4((5 * 6)/2)
Now multiply 5 * 6 to get 30.
25 + 4(30/2)
Then divide 30 by 2 to get 15.
25 + 4(15)
Now multiply 4 by 15 to get 60.
25 + 60
Lastly, add 25 and 60 to get 85.
The entire square pyramid's surface area is 85 square meters.
I hope this helps! ヽ(*⌒▽⌒*)ノ