we have that
The area of the triangle EFG is equal to the area of the rectangle minus the area of the three interior right triangles
so
Step 1
Find out the area of the rectangle
A=(6)(7)=42 unit2
Step 2
Find out the area of the three interior triangles
A=(1/2)[(1)(7)+(5)(2)+(5)(6)]
A=(1/2)[7+10+30]
A=23.5 unit2
Step 3
The area of the triangle EFG is equal to
A=42-23.5=18.5 unit2
therefore
The area of triangle EFG is 18.5 unit2
