Question: Construct a parallelogram ABCD in which $AB=10$ cm, $AD=BC=6.5$ cm, $\angle BAD=110^\circ$, and $\angle ABC=70^\circ$. Measure the length $AC$. Construct the locus of points within parallelogram ABCD which are (1) $x$ cm from $AB$, (2) $y$ cm from $C$, (3) equidistant from $BC$ and $CD$. A point $Z$ within parallelogram ABCD is such that its distance is less than or equal to $x$ cm from $AB$, less than or equal to $y$ cm from $C$, and nearer to $CD$. Clearly indicate by shading and label BC and CD.
1. **State the problem:** Construct parallelogram $ABCD$ with $AB=10$ cm, $AD=6.5$ cm, $\angle BAD=110^\circ$, and $\angle ABC=70^\circ$. Then measure diagonal $AC$ and construct loci of points inside the parallelogram based on given distance conditions.
2. **Construct parallelogram $ABCD$:**
- Draw segment $AB=10$ cm.
- At point $A$, construct angle $110^\circ$ and draw ray $AD$.
- On ray $AD$, mark point $D$ such that $AD=6.5$ cm.
- Since $ABCD$ is a parallelogram, $BC$ is parallel and equal to $AD$, so draw $BC$ parallel to $AD$ with length $6.5$ cm.
- Connect points $C$ and $D$ to complete parallelogram.
3. **Measure diagonal $AC$:**
- Use the law of cosines in triangle $ABC$ or measure directly.
- Using law of cosines:
$$AC^2 = AB^2 + BC^2 - 2 \times AB \times BC \times \cos(\angle ABC)$$
$$= 10^2 + 6.5^2 - 2 \times 10 \times 6.5 \times \cos 70^\circ$$
$$= 100 + 42.25 - 130 \times 0.3420 = 142.25 - 44.46 = 97.79$$
$$AC = \sqrt{97.79} \approx 9.89 \text{ cm}$$
4. **Construct locus of points:**
- (a) Points $x$ cm from $AB$: This is a line parallel to $AB$ at distance $x$ inside the parallelogram.
- (b) Points $y$ cm from $C$: This is a circle centered at $C$ with radius $y$.
- (c) Points equidistant from $BC$ and $CD$: This is the angle bisector of angle $C$ inside the parallelogram.
5. **Point $Z$ conditions:**
- Distance from $AB \leq x$ cm.
- Distance from $C \leq y$ cm.
- Closer to $CD$ than $BC$.
6. **Shade the region:**
- Shade the area inside the parallelogram satisfying all above conditions.
- Label sides $BC$ and $CD$ clearly.
**Final answer:**
- Length $AC \approx 9.89$ cm.
- Loci constructed as described.
- Region for point $Z$ shaded accordingly.