Position and label triangles for use in coordinate

• Position and label triangles for use in coordinate proofs. • Write coordinate proofs.

Content Standards G. CO. 10 Prove theorems about triangles. G. GPE. 4 Use coordinates to prove simple geometric theorems algebraically. Mathematical Practices 3 Construct viable arguments and critique the reasoning of others. 2 Reason abstractly and quantitatively.

• coordinate proof

Position and Label a Triangle Position and label right triangle XYZ with leg d units long on the coordinate plane. Use the origin as vertex X of the triangle. Place the base of the triangle along the positive x-axis. Position the triangle in the first quadrant. Since Z is on the x-axis, its y-coordinate is 0. Its x-coordinate is d because the base is d units long.

Position and Label a Triangle Since triangle XYZ is a right triangle, the x-coordinate of Y is 0. We cannot determine the y-coordinate, so call it b. Answer:

What would be the best way to position and label equilateral triangle ABC with side w units long on the coordinate plane?

Identify Missing Coordinates Name the missing coordinates of isosceles right triangle QRS.

Name the missing coordinates of isosceles right ΔABC.

Finish the following coordinate proof to prove that the segment drawn from the right angle to the midpoint of the hypotenuse of an isosceles right triangle is perpendicular to the hypotenuse.

Homework Page 307 (13 -18, 21)