9.1
Name: ............................
Date: ............................
TRIANGLES A. Types of Triangles 1. TYPES OF TRIANGLES BASED ON THE LENGTHS OF THE SIDES F
C
P R
A
B (a)
E
D (b)
Q (c)
Look at the above figure. a. Use a ruler to measure the lengths of the sides of ∆ABC.
b. Are there any equal sides? If so, how many are they? c. By looking at the lengths of the sides, what is ∆ABC? Explain it. d. Repeat questions (a) to (c) for ∆DEF. e. Repeat questions (a) to (c) for ∆PQR.
Solution:
80 / Student’s Worksheet – Triangles
2. TYPES OF TRIANGLES BASED ON THE MEASURES OF THE ANGLES A
B
K
L
C (a)
(b)
R
M
P (c)
Q
Look at the above figure. Use a protractor to answer the following questions. a. Measure the sizes of the angles of ∆ABC. b. Is there any 90° angle?
c. What are the sizes of the other two angles? d. By observing the size of the angles, what kind of triangle is ∆ABC? Explain
it. e. Repeat questions (a) to (d) for ∆KLM. f. Repeat questions (a) to (d) for ∆PQR.
Solution:
81 / Student’s Worksheet – Triangles
3. TYPES OF TRIANGLES BASED ON THE PROPERTIES B
L R
A
(a)
C
K
(b)
M
P
Q (c)
Look at the above figure. Use a protractor and a ruler to answer the following questions. a. Find the measures of the angles of ∆ABC. b. Measure the lengths of the sizes of ∆ABC. c. Are there any equal sides in ∆ABC? d. Is there any 90° angle in ∆ABC? e. What are the measures of the other two angles? f. By observing the angles, what shape is ∆ABC? g. By observing the lengths of the sides, what shape is ∆ABC? h. By observing the angles and the sides, what shape is ∆ABC? Explain it. i. Repeat questions (a) to (h) for ∆KLM. j. Repeat questions (a) to (h) for ∆PQR. k. Can you find other kinds of triangle in this grouping? Explain.
Solution:
Mathematics for Junior High School Year 7 / 82