Task B-4.3. Let $A B C A^{\prime} B^{\prime} C^{\prime}$ be a right regular triangular prism. The length of the base edge $A B C$ is $10 \mathrm{~cm}$, and the height of the prism is $10 \sqrt{2} \mathrm{~cm}$. Point $D$ is the midpoint of edge $\overline{A B}$. Calculate the measure of angle $D A^{\prime} C$.