BIG idea Reasoning and Proof
You can use proven theorems to explore relationships among sides, angles, and special
lines and segments in triangles.
Task 2
a. Draw triangle ABC with obtuse angle C and construct its orthocenter O. Then find the
orthocenters of triangle ABO, triangle ACO, and triangle BCO. What did you discover? Explain why
you get this result.
b. Will your conjecture be true for any acute or right triangle ABC? Explain your reasoning.