This is a solution to a problem from American Mathematics Competition (AMC) 8 2020 Problem 18 based on Geometry.
In the cube $ABCDEFGH$ with opposite vertices $C$ and $E,$ $J$ and $I$ are the midpoints of edges $\overline{FB}$ and $\overline{HD},$ respectively. Let $R$ be the ratio of the area of the cross-section $EJCI$ to the area of one of the faces of the cube. What is $R^2?$
(A) $\frac{5}{4}$ (B) $ \frac{4}{3} $ (C) $ \frac{3}{2} $ (D) $ \frac{25}{16}$ (E) $\frac{9}{4}$.
