Solutions: Section 2.9 (Measuring Angles)

Figure it Out (Page 35)

Q1. Write the measures of the following angles: a. $\angle KAL$ b. $\angle WAL$ c. $\angle TAK$

Solution:

• a. $\angle KAL = 30^\circ$
• b. $\angle WAL = 50^\circ$
• c. $\angle TAK = 120^\circ$

Page 36 Exercise

Q. Name the different angles in the figure and write their measures.

Solution:

• $\angle POQ = 35^\circ$
• $\angle POR = 95^\circ$
• $\angle POS = 125^\circ$
• $\angle POT = 160^\circ$
• $\angle QOR = 60^\circ$ (Difference between 95 and 35)
• $\angle QOS = 90^\circ$ (Difference between 125 and 35)
• $\angle QOT = 125^\circ$
• $\angle QOU = 145^\circ$
• $\angle ROS = 30^\circ$
• $\angle ROT = 65^\circ$
• $\angle ROU = 85^\circ$
• $\angle SOT = 35^\circ$
• $\angle SOU = 55^\circ$
• $\angle TOU = 20^\circ$

Page 45 (Text Page 33/34 Figure it Out)

Q1. Angles in a clock:

• a. 1 o’clock: The angle is $360^\circ \div 12 = 30^\circ$.
• b. 2 o’clock: $60^\circ$. 4 o’clock: $120^\circ$. 6 o’clock: $180^\circ$.
• c. 3 o’clock: $90^\circ$. 9 o’clock: $270^\circ$.

Q2. The angle of a door: Answer: Yes. The vertex is the hinge/joint where the door meets the wall. The arms are the bottom edge of the door and the bottom edge of the wall.

Q4. Toy with slanting slabs: Answer: Yes, angles describe slopes. Larger angle = steeper slope.

• Arms: One arm is the side of the toy structure, the other is the slanting slab.