warm up *use your notes from yesterday to guide your thinking!
TRANSCRIPT
Geometry/Trig
Name: ______________________________
Date: _______________________________
Lesson 2-2 Properties of Triangles
Learning Goals: (4) What is the sum of all of the interior angles in a triangle? (5) How do you classify
the different types of triangles by angles? (6) How do you classify the different types of triangles by sides?
Warm Up *use your notes from yesterday to
guide your thinking!
1. Name the indicated angle in three different ways:
2. Name the angle relationship shown:
3. Using the picture below, determine the measure of each angle that’s listed.
____________ Angles _______________
_______________ Angles ______________ Angles
Geometry/Trig
Discover it!
Angles of a Triangle
What do you notice about all three angles in ∆ABC?
The sum of the interior angles in a triangle is _____________.
Apply it!
1. What is the measure of ∠𝐶?
2. In ∆ABC, m∠A = 42° and m∠C = 63°. What is the measure of ∠B?
3. In ∆ABC, m∠A = x° and m∠B = 2x+2° and m∠C = 3x+4°, what is the value of x?
Geometry/Trig
Classifying Triangles by their Interior Angles (from your video lesson!)
Apply it!
Classify the following triangle using angles : 4. The angles of a triangle measure 350, 510, and 940. Is the triangle acute, obtuse, or right? Justify your answer.
Classifying by Sides::
No Congruent
Sides
2 Congruent
Sides
3 (all)
Congruent Sides
Remember!
“Justify” means
to write out your
thinking!
Geometry/Trig
Apply it!
5. The sides of a triangular garden measure 150 inches, 160 inches, and 175 inches. Is the garden an isosceles,
scalene, or equilateral? Justify your answer.
6. Classify all of the following triangles according to its sides.
Now, Master It!
7. In ∆ABC, m∠A = 2x° and m∠B = 2x+2° and m∠C = 3x+4°, what is the value of x to the nearest tenth of a
degree? Is the triangle acute, right, or obtuse – explain your reasoning.
This triangle is a ______________
triangle because it has
_____________________________
This triangle is a ______________
triangle because it has
_____________________________
This triangle is a ______________
triangle because it has
_____________________________
This triangle is a ______________
triangle because it has
_____________________________
Geometry/Trig
Name:______________________________
Date:___________
2-2 Homework
1. The angles of a triangle a given triangle are: 1010, 510, and 280. Is this triangle
acute, obtuse or right?
Fill in the blanks: According to its angles, triangle is _____________________,
because it contains _________________________________________________________________.
2. Classify the following triangle by its angles. (Acute, obtuse, or right).
This triangle is ___________________ because it contains_____________________________________.
3. Given Triangle ABC, 𝑚∡A = 30°, 𝑚∡B = 2x°, 𝑚∡C = 70°
a. find the measurement of ∠B.
b. Is triangle ABC acute, obtuse, or right?
c. According to its angles, Triangle ABC is __________________________ because _____________________________
___________________________________________________________________________.
Geometry/Trig
4. Classify the following triangles by their sides:
a) b)
5. Classify each triangle by its angles and sides
Diagram Classify by angles Classify by Sides
6. In ΔABC, 𝑚∡A = 30° and 𝑚∡B = 50°. What is the measure of angle C?