What is the area of this triangle ?

Answer:
21 units^2
Step-by-step explanation:
The area of the triangle is
A = 1/2 bh
The base is on the left side and is 6 units
The height is from left to right and is 7 units ( the left side to the point x3,y3)
A = 1/2 (6) (7)
A = 21 units^2