They are always on a coplanar
Answer: 
Have attached the picture for explanation...
Answer:
the answer is n, 225 so u can use another app to make sure u find ur answer
Answer:
For the first blank: 8
For the second blank: I think it's 913
Step-by-step explanation:
First blank: To find the area of a square do (Length * Width) For the roof do 15 * 25 to get 375. Then divide by 100 and you get 3.75 but round to 4
That's for 1 half of the roof so do cover the whole roof you need 8.
The length can be found using the Pythagorean Theorem...
c^2=a^2+b^2 and in this case:
d^2=(dx^2)+(dy^2)
d^2=(3-7)^2+(12-9)^2
d^2=-4^2+3^2
d^2=16+9
d^2=25
d=5
So the length of AB=5 units.