Answer:
[tex]48 cm^2[/tex]
Step-by-step explanation:
Each of the small triangles are right, so we can add up all the small triangle's areas to find the total area.
The 4-by-10 triangle: The area is [tex]4*10/2=40/2=20[/tex].
The other 4-by-10 triangle has the same side lengths and hence the same area, so the area is [tex]20[/tex].
The 4-by-4 triangle: The area is [tex]4*4/2=8/2=4[/tex].
The other 4-by-4 triangle has the same area, [tex]4[/tex].
The total area is [tex]20+20+4+4=\boxed{48} cm^2[/tex].
