Coordinating Geometry

Coordinating Geometry?
I need help figuring these questions out badly! I always get these types of question's wrong on test's and work sheet's! so if someone can help me understand then I would appreciate it alot!

Question 1:
A triangle is considered a right triangle if two of its legs are perpendicular to each other. Below is the graph of three lines that form a triangle.

http://i40.tinypic.com/262qoad.gif <<<< graph

Part 1: Find the slopes of all three legs of the triangle shown.

Part 2: Are any of the legs perpendicular to each other? If so, which ones and how do you know? Make sure to use complete sentences and correct grammar.


Question 2:
The height of a triangle can be found by drawing a perpendicular line from a vertex to a base. A triangle, along with its height, is shown on the graph below.

http://i39.tinypic.com/24oaufn.gif <<<<<< graph

Part 1: Find the slopes of the lines representing the height and the base shown.

Part 2: Is the height shown the true height of the triangle? How do you know? Make sure to use complete sentences and correct grammar.