Question

This is called Area of a triangle on a coordinate grid

Answer 1

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