Select from the drop-down menus to correctly complete the statements. By the triangle sum property, the sum of the measures of angles 2, 3, and 4 is °__?__(90, 180). The sum of the measures of angles__?__(1 and 2, 1 and 4, 2 and 3, 3 and 4) is 180° because they form a linear pair. Using the substitution property, m∠2+m∠3+m∠4=m∠1+m∠4 . Then, by the subtraction property of equality, m∠2+m∠3=m∠_?_(1, 4) .