Here are the solutions to the problems: 3. The combined angle measure is $70^\circ$. The two given angles are $45^\circ$ and $f^\circ$. Step 1: Set up the equation based on the sum of the angles. $$45^\circ + f^\circ = 70^\circ$$ Step 2: Solve for $f$. $$f^\circ = 70^\circ - 45^\circ$$ $$f^\circ = 25^\circ$$ The value of $f$ is $\boxed{\text{25}}$. 4. The combined angle measure is $115^\circ$. The two given angles are $t^\circ$ and $90^\circ$ (indicated by the right angle symbol). Step 1: Set up the equation based on the sum of the angles. $$t^\circ + 90^\circ = 115^\circ$$ Step 2: Solve for $t$. $$t^\circ = 115^\circ - 90^\circ$$ $$t^\circ = 25^\circ$$ The value of $t$ is $\boxed{\text{25}}$. 5. The combined angle measure is $180^\circ$ (a straight angle). The two given angles are $x^\circ$ and $150^\circ$. Step 1: Set up the equation based on the sum of the angles. $$x^\circ + 150^\circ = 180^\circ$$ Step 2: Solve for $x$. $$x^\circ = 180^\circ - 150^\circ$$ $$x^\circ = 30^\circ$$ The value of $x$ is $\boxed{\text{30}}$. 6. The two given angles, $35^\circ$ and $r^\circ$, form a right angle, which measures $90^\circ$. Step 1: Set up the equation based on the sum of the angles. $$35^\circ + r^\circ = 90^\circ$$ Step 2: Solve for $r$. $$r^\circ = 90^\circ - 35^\circ$$ $$r^\circ = 55^\circ$$ The value of $r$ is $\boxed{\text{55}}$. 7. Problem Solving Step 1: Determine the angle between each number on a clock face. A full circle is $360^\circ$, and there are 12 numbers on a clock. Angle per number = $\frac{360^\circ}{12} = 30^\circ$. Step 2: Identify the positions of the line and the minute hand. The line is drawn to the number 12. The minute hand is on 2. Step 3: Calculate the angle between the line at 12 and the minute hand at 2. The minute hand moves 2 positions from 12 (from 12 to 1, and from 1 to 2). Angle = $2 \times 30^\circ = 60^\circ$. The angle is $\boxed{\text{60}^\circ}$. 8. Test Practice The combined angle measure is $120^\circ$. The two given angles are $n^\circ$ and $80^\circ$. Step 1: Set up the equation based on the sum of the angles. $$n^\circ + 80^\circ = 120^\circ$$ Step 2: Solve for $n$. $$n^\circ = 120^\circ - 80^\circ$$ $$n^\circ = 40^\circ$$ The value of $n$ is $40$. Comparing this to the given options: A) 45 B) 40 C) 35 D) 30 The correct option is B).