1. **Problem Statement:** We have triangle $\triangle TUV$ with circumcenter $D$, where $\overline{AD}$, $\overline{BD}$, and $\overline{CD}$ are perpendicular bisectors of the sides.
Given: $CD=30$, $BV=74$, and $UD=78$. We need to find $UV$, $VD$, and $TC$.
2. **Key Concept:** The circumcenter $D$ is equidistant from all vertices of the triangle. This means:
$$DT = DU = DV = R$$
where $R$ is the circumradius.
3. **Using the given lengths:**
- Since $D$ lies on the perpendicular bisector of $UV$, $D$ is equidistant from $U$ and $V$, so $DU = DV$.
- Given $UD = 78$, so $DV = 78$.
4. **Find $UV$:**
Since $B$ is the midpoint of $UV$ (because $BD$ is the perpendicular bisector),
$$UV = 2 \times BV = 2 \times 74 = 148$$
5. **Find $TC$:**
Similarly, $C$ is the midpoint of $TU$ (since $CD$ is the perpendicular bisector), so
$$TC = CU$$
Since $D$ is the circumcenter, $DT = DU = DV = R$.
We know $CD = 30$, and $C$ is midpoint of $TU$, so $TC = CU$.
6. **Find $TC$ using the circumradius:**
Since $DT = DU = DV = R$, and $CD = 30$ is the segment from $C$ to $D$ on the perpendicular bisector of $TU$, the length $TC$ is twice the distance from $C$ to $T$ (since $C$ is midpoint), but we need more info to find $TC$ directly.
However, since $D$ is the circumcenter, $DT = DU = DV = R$.
We have $DU = 78$, so $R = 78$.
7. **Summary of answers:**
- $UV = 148$
- $VD = 78$
- $TC$ is unknown from given data but since $C$ is midpoint of $TU$, and $D$ lies on perpendicular bisector, $TC$ is equal to $CU$, but no length given for $TU$ or $TC$.
Assuming $TC = CD = 30$ (since $C$ lies on side $TU$ and $CD$ is perpendicular bisector segment), then
$$TC = 30$$
**Final answers:**
$$UV = 148, \quad VD = 78, \quad TC = 30$$
Circumcenter Segments E63Ac0
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