Download Lesson 5 –Classifying Triangles Examples Exercises

Name
Date
Period
Homework
Geometry & Probability
Unit B
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Lesson 5 –Classifying Triangles
Acute triangle
All acute angles
right triangle
1 right angle
obtuse triangle
1 obtuse angle
Scalene triangle
No congruent sides
isosceles triangle
at least 2 congruent sides
equilateral triangle
3 congruent sides
Examples
20
The figure shows a triangular pennant tied to a pole.
Classify the marked triangle by its angles and by its sides.
The triangle has three acute angles and two sides the same length.
So, it is an acute, isosceles triangle.
Exercises
Classify the marked triangle in each object by its angles and by its sides.
25°
40°
30°
30°
50°
1. __________________
2. _________________
3. __________________
Draw a triangle that satisfies each set of conditions. Then classify each triangle.
4.
a triangle with three acute angles and
three congruent sides
4. ________________________
5.
a triangle with one right angle
and no congruent sides
5. ______________________
6. TAILORING Each lapel on a suit jacket is in the shape of a triangle. The three angles of each triangle
measure 47°, 68°, and 65°. Classify the triangle by its angles.
7. FLAGS A naval distress signal flag is in the shape of a triangle. The three sides of the triangle
measure 5 feet, 9 feet, and 9 feet. Classify the triangle by its sides.
page 2
G&P Unit B Lesson 5
Extra Practice
Find the value of x. Then classify the triangle by its angles.
1.
81°
84°
x°
2.
3.
x°
36°
24°
x°
49°
4.
x°
38°
5.
6.
x°
71°
65°
38°
x°
51°
7.
57°
8.
9.
x°
126°
x°
45°
50°
22°
x°
Draw a triangle that satisfies each set of conditions. Then classify each triangle.
10. a triangle with one obtuse angle and no congruent sides
______________________
11. a triangle with three acute angles and three congruent sides
12. a triangle with one right angle and two congruent sides
_________________
______________________