Triangle Variables
1. **State the problem:** We have two congruent triangles \(\triangle RWS \cong \triangle TUV\). We need to find the values of \(x\) and \(y\) given the angles and sides.
2. **Identify corresponding parts:** Since the triangles are congruent, corresponding angles and sides are equal.
- Angle \(R\) corresponds to angle \(T\).
- Angle \(S\) corresponds to angle \(V\).
- Side \(WS\) corresponds to side \(UV\).
3. **Use the given information:**
- Angle \(R = (8x - 27)^\circ\)
- Angle \(V = 29^\circ\)
- Side \(VT = (3y + 7)\)
4. **Find angle \(S\):** Since \(\triangle RWS\) is right angled at \(W\), angle \(W = 90^\circ\).
Sum of angles in a triangle is \(180^\circ\), so
$$
(8x - 27) + 90 + S = 180
$$
Simplify:
$$
S = 180 - 90 - (8x - 27) = 90 - 8x + 27 = 117 - 8x
$$
5. **Corresponding angles are equal:**
Angle \(S = \) angle \(V = 29^\circ\), so
$$
117 - 8x = 29
$$
Solve for \(x\):
$$
8x = 117 - 29 = 88
$$
$$
x = \frac{88}{8} = 11
$$
6. **Find side \(WS\):** Given \(WS = 20\) and corresponds to side \(UV\).
7. **Find side \(VT\):** Given \(VT = 3y + 7\) and corresponds to side \(RW = 15\).
Set equal:
$$
3y + 7 = 15
$$
Solve for \(y\):
$$
3y = 15 - 7 = 8
$$
$$
y = \frac{8}{3} \approx 2.67
$$
**Final answers:**
$$
x = 11, \quad y = \frac{8}{3}$$