1. We will determine1 missing measurements of Isosceles2 and Equilateral3 Triangles.
Notes with Whiteboard
LEARNING OBJECTIVE
Definition
1 figure out
2 having two sides of equal length.
3 having all its sides of the same length.
Declare the Objective
B read the objective to A

2. ACTIVATE PRIOR KNOWLEDGE
Remember the Concept
Isosceles Triangle Theorem If two sides of a triangle are congruent, then the angles opposite those sides are congruent.
Triangle Sum Theorem states that the three interior angles of any triangle add up to 180.  
Find the angle measure: 1. 2
ACTIVATE PRIOR KNOWLEDGE
Make the Connection
Students, you already know how apply Isosceles Triangle Theorem. Today, we will learn how to find the missing measurements of Isosceles and Equilateral Triangles.

3. Same Same Same Check for Understanding A explain to B how to find DE?
CONCEPT DEVELOPMENT
Same
Same
Same
Check for Understanding
A explain to B how to find DE?

4. What is the length of each side
Remember the Concept
3 simple steps to subtract fractions:
1. Make sure the bottom numbers (the denominators) are the same.
2. Subtract the top numbers (the numerators). Put the answer over the same denominator.
3. Simplify the fraction (if needed).
CONCEPT DEVELOPMENT x
Check for Understanding
B explain to A how to find Side Length?

5. What is the length of each side
Remember the Concept
3 simple steps to subtract fractions:
1. Make sure the bottom numbers (the denominators) are the same.
2. Subtract the top numbers (the numerators). Put the answer over the same denominator.
3. Simplify the fraction (if needed).
CONCEPT DEVELOPMENT

6. Is the triangle an acute, isosceles, obtuse, or right triangle?
CONCEPT DEVELOPMENT
Find the missing angle:
= = 106
Check now:
One of the angle measures is greater than 90° and two angles are same . So the triangle is an Obtuse Isosceles triangle.
Find the missing angle:
= =
Check now:
Check for Understanding
B explain to A how to classify triangle?
All of the angle measures are less than 90°. So the triangle is an acute isosceles triangle.

7. Step 1: Isolate the absolute value expression.
Recall that the absolute value |x| of a number is its distance from on the number line. 
Step 1: Isolate the absolute value expression.
Step 2: Set the quantity inside the absolute value notation equal to + and –.
Step 3: Solve for the unknown in both equations. + - + -
Check for Understanding
A explain to B how to solve absolute value equations?

8. What did you learn today about determine missing measurements of Isosceles and Equilateral Triangles.
Word Bank
Isosceles Triangle Theorem
Triangle Sum Theorem
Isosceles Triangles
Equilateral Triangles
Subtracting fractions
Absolute value equation
SUMMARY CLOSURE