It is given that cap d is the midpoint of line segment AB and cap e is the midpoint of line segment AC To prove that DE is half the length of BC , the distance formula, d is equal to square root of open paren x sub 2 minus x sub 1 close paren squared plus open paren y sub 2 minus y sub 1 close paren squared end root , can be used to determine the lengths of the two segments. The length of line segment BC can be determined with the equation BC is equal to square root of open paren 2 A minus 0 close paren squared plus open paren 0 minus 0 close paren squared end root , which simplifies to 2 A The length of line segment DE can be determined with the equation DE is equal to square root of open paren A plus b minus b close paren squared plus open paren c minus c close paren squared end root , which simplifies to ________. Therefore, BC is twice DE , and DE is half BC Which is the missing information in the proof?