The figure shows a parallelogram ABCD.
If squares of area S_{1}, S_{2}, S_{3}, and S_{4} are constructed on the
sides and diagonals, prove that 2S_{1} + 2S_{2}
= S_{3} + S_{4}
.
View or post a solution.
See also:
Median length, Apollonius' Theorem
Pythagoras Theorem
Euclid's Elements Book II Proposition 13
Stewart Theorem
