Name:



Name: ________________________ Date: ___________________ Hr: ____________

Unit 4 WS #1 Angles in a Triangle

Part I: Angle Sums

|1. Measure the angles in each triangle below. Place your |Triangle |A |B |C |Sum |

|measurements in the table. Then, for each triangle, find the sum of| | | | | |

|the three measures. | | | | | |

| |1 | | | | |

| |2 | | | | |

| |3 | | | | |

| |4 | | | | |

2. What is the pattern? The three angles in a triangle always add up to ___________.

3. Use your protractor to draw a triangle (ΔABC) with (A = 60° and (B = 20° in the space at right.

(a) Use reasoning: What do you THINK the measure of (C should be? ________

(b) Now measure (C. How close was your prediction?

4. Use your protractor to draw a triangle (ΔDEF) with (D = 45° and (E = 55° in the space at right.

(a) Use reasoning: What do you THINK the measure of (F should be? ________

(b) Now measure (F. How close was your prediction?

Part II: Classifying Triangles

5. Triangles can be classified by their side lengths or by their angles. Write a brief definition of each of the following types of triangles. Then draw a sample picture of each.

By Side Length: By Angle:

(a) Scalene Triangle (d) Right Triangle

(b) Isosceles Triangle (e) Obtuse Triangle

(c) Equilateral Triangle (f) Acute Triangle

6. Identify each of the following triangles as scalene, isosceles, or equilateral. Then identify them as right, obtuse, or acute.

|a. |b. |c. |

|[pic] |[pic] |[pic] |

| | | |

|____________________ |____________________ |____________________ |

|____________________ |____________________ |____________________ |

|d. |e. Draw an isosceles right triangle. |f. Draw an obtuse scalene triangle. |

|[pic] | | |

|____________________ | | |

|____________________ | | |

7. A triangle with no sides congruent is a(n) _____________________ triangle.

8. A triangle with all sides congruent is a(n) _____________________ triangle.

9. A triangle with at least two sides congruent is a(n) ______________ triangle.

10. A triangle with a 90( angle is a(n) _________________________ triangle.

11. A triangle with two 40( angles is a(n) ________________________ triangle.

12. A triangle with three equal sides is a(n) _____________________ triangle.

13. A triangle with 40(, 60(, 80( angles is a(n) _____________________ triangle.

14. Is it possible for an triangle to have TWO obtuse angles? Why or why not?

15. Is it possible for a right triangle to have an obtuse angle? Why or why not?

16. Fill in the blanks with the appropriate number: A triangle can have AT MOST _________ obtuse angle(s). A triangle can have AT MOST _________ acute angle(s). A triangle can have AT MOST __________ right angle(s).

[pic]

[pic]

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download