ABCD and
diagonals AC and BD are given. DC is congruent to BC and DE is congruent to BE,
therefore, EC is congruent to EC. Angle DEC’s congruent to angle BEC, angle DEC
- BEC = 180, and angle DEC= angle BEC is equal to 90 degrees, so this proves
that DEC and BEC are right angles. I am hoping that this answer
has satisfied your query and it will be able to help you, and if you would
like, feel free to ask another question.
