standard_description: Use coordinates to prove simple geometric theorems algebraically. For example, prove or disprove that a figure defined by four given points in the coordinate plane is a rectangle; prove or disprove that the point (1, Ö3) lies on the circle centered at the origin and containing the point (0, 2).
problem_activity: Task
Three unit squares and two line segments connecting two pairs of
vertices are shown. What is the area of $\triangle ABC$?
[IMG]


aligns: yes