Perpendicular lines form right angles

Substitution

Algebra

Definition

The base angles of an isosceles trapezoid are equal

ASA (Angle-Side-Angle)

Segment addition theorem

Substitution

Substitution

Definition

BA = CD

AP = BP and DQ = CQ

BA = BP + AP and CD = CQ + DQ

BA = 2(PA) and CD = 2(QD)

PA = (1/2)BA and QD = (1/2)CD

PA = (1/2)BA and QD = (1/2)BA

PA = QD

Angle APG = Angle EQD = 90

Angle A = Angle D

Triangle AGP is congruent to triangle DEQ