A B C A 4 0 9/4 4 0 3 0 0
From the other tutor response, you just know that the coordinates of the point C are C = (9/4,0). Now notice that the triangle ABC has the side AC lying at the x-axis. Its length is- = - = . The altitude drawn from the point B to the side AC is 3 units long. So, the area of the triangle ABC is = square units.