Triangle GHI, with vertices G(4,-8), H(8,-9), and I(5,-6), is drawn inside a rectangle, as shown below ,What is the area, in square units, of triangle GHI?

Answer:
Hello,
Answer 9/2
Step-by-step explanation:
Let's put some points:
A=(4,-6)
B=(8,-6)
C=(4,-9) (the vertex of the rectangle)
AI=1, IB=3,AB=4
AG=2,GC=1
Area of the triangle AIG=1*2/2=1
Area of the triangle IBH=3*3/2=9/2
Area of the triangle GCH=1*4/2=2
Area of the rectangle=4*3=12
Area of the triangle IGH=12-1-9/2-2=9/2 (unit²)