1. **Problem Statement:** Find the measures of the other angles of a parallelogram if one angle measures 78°. 2. **Formula and Properties:** - Opposite angles in a parallelogram are equal. - Consecutive angles in a parallelogram are supplementary, meaning their sum is 180°. 3. **Step-by-step Solution:** 1) Given one angle $\angle A = 78^\circ$. 2) Since opposite angles are equal, the angle opposite to $\angle A$ is also $78^\circ$. 3) Consecutive angles are supplementary, so the angle adjacent to $\angle A$ is: $$ \angle B = 180^\circ - 78^\circ = 102^\circ $$ 4) The angle opposite to $\angle B$ is equal to $\angle B$, so: $$ \angle D = 102^\circ $$ 4. **Final Answer:** The four angles of the parallelogram are: $$ 78^\circ, 102^\circ, 78^\circ, 102^\circ $$