1. **Problem 31:** Given triangle ABC with angles $m\angle A = X$, $m\angle B = 2X$, and $m\angle C = 2X + 30^\circ$. Find $m\angle B$.
2. The sum of angles in any triangle is $180^\circ$. So,
$$X + 2X + (2X + 30) = 180$$
3. Simplify the equation:
$$X + 2X + 2X + 30 = 180$$
$$5X + 30 = 180$$
4. Subtract 30 from both sides:
$$5X + \cancel{30} - \cancel{30} = 180 - 30$$
$$5X = 150$$
5. Divide both sides by 5:
$$\frac{5X}{\cancel{5}} = \frac{150}{\cancel{5}}$$
$$X = 30$$
6. Find $m\angle B = 2X = 2 \times 30 = 60^\circ$.
---
7. **Problem 32:** Triangle SAD with $m\angle S = 2x$, $m\angle A = x - 23$, $m\angle D = x - 17$. Find $m\angle S$.
8. Sum of angles:
$$2x + (x - 23) + (x - 17) = 180$$
9. Simplify:
$$2x + x - 23 + x - 17 = 180$$
$$4x - 40 = 180$$
10. Add 40 to both sides:
$$4x - \cancel{40} + \cancel{40} = 180 + 40$$
$$4x = 220$$
11. Divide both sides by 4:
$$\frac{4x}{\cancel{4}} = \frac{220}{\cancel{4}}$$
$$x = 55$$
12. Find $m\angle S = 2x = 2 \times 55 = 110^\circ$.
---
13. **Problem 33:** Right triangle XYZ with right angle at X, $m\angle Y = x + 5$, $m\angle Z = x - 7$. Find $m\angle Z$.
14. Sum of angles in triangle:
$$90 + (x + 5) + (x - 7) = 180$$
15. Simplify:
$$90 + x + 5 + x - 7 = 180$$
$$2x + 88 = 180$$
16. Subtract 88:
$$2x + \cancel{88} - \cancel{88} = 180 - 88$$
$$2x = 92$$
17. Divide by 2:
$$\frac{2x}{\cancel{2}} = \frac{92}{\cancel{2}}$$
$$x = 46$$
18. Find $m\angle Z = x - 7 = 46 - 7 = 39^\circ$.
---
19. **Problem 34:** Triangle QRS is equilateral (all sides congruent), so all angles equal.
20. Sum of angles:
$$m\angle Q + m\angle R + m\angle S = 180$$
21. Since all equal:
$$3 \times m\angle Q = 180$$
22. Divide by 3:
$$m\angle Q = \frac{180}{3} = 60^\circ$$
23. So,
$$m\angle Q = m\angle R = m\angle S = 60^\circ$$
---
24. **Problem 35:** Triangle WXY with $m\angle W = x - 22$, $m\angle X = 3x + 19$, $m\angle Y = x - 17$. Find $m\angle X$.
25. Sum of angles:
$$(x - 22) + (3x + 19) + (x - 17) = 180$$
26. Simplify:
$$x - 22 + 3x + 19 + x - 17 = 180$$
$$5x - 20 = 180$$
27. Add 20:
$$5x - \cancel{20} + \cancel{20} = 180 + 20$$
$$5x = 200$$
28. Divide by 5:
$$\frac{5x}{\cancel{5}} = \frac{200}{\cancel{5}}$$
$$x = 40$$
29. Find $m\angle X = 3x + 19 = 3 \times 40 + 19 = 120 + 19 = 139^\circ$.
---
**Final answers:**
- $m\angle B = 60^\circ$
- $m\angle S = 110^\circ$
- $m\angle Z = 39^\circ$
- $m\angle Q = m\angle R = m\angle S = 60^\circ$
- $m\angle X = 139^\circ$
Triangle Angles 680951
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.