Day 1 Isosceles Triangle CW HW.notebook
November 19, 2014
Do Now
1. Define an isosceles triangle.
2. Define a scalene triangle.
Analytic Proofs
Objective: Students will be able to prove that a triangle is either isosceles or scalene by using an analytic proof.
Day 1 Isosceles Triangle CW HW.notebook
November 19, 2014
Welcome to Analytic Geometric Proofs ...YAY!
Yes, you must follow this format every time!
1. Graph the figure
2. Write out the property that you will be using to show that the quadrilateral is a parallelogram, rectangle, rhombus, square, or trapezoid OR triangle is isosceles, scalene, right or isosceles right
3. Write the formulas you will need
4. Do the math calculations
5. Draw conclusions based on your diagram
6. Write the (therefore) statement
Given: ABC with A (5, 7), B (2, 3), and C (1, 4)
Prove:
ABC is isosceles
y
x
If a triangle has two congruent sides, then it is an isosceles triangle.
Day 1 Isosceles Triangle CW HW.notebook
November 19, 2014
2. Given: ABC with A (­3, 6), B (­9, 0), and C (9, 0)
Prove:
x
ABC is scalene
y
If a triangle has no congruent sides, then it is a scalene triangle.