17. Find the area of the walls

The walls of a living room are painted with identical triangular patterns. One such triangle has the vertices $(- 3, 0)$, $(- 10, -8)$ and $(6, 7)$. If the walls of the room are entirely covered by 117 triangles, then find the area of the walls.

 

 

Answer:

 

Area of the walls $=$  square units.