[أحمد سعد الدين]

Problem 215.
Quadrilateral, Angle Bisectors, and Cyclic Quadrilateral




###########

[أحمد سعد الدين]

Problem 43. Angles, Triangle. Level: High School, SAT Prep, College
In the figure, AB = BC = CD, and the measure of angle C is double the measure of angle A. Prove that x = 60°.



#############

[أحمد سعد الدين]

Problem 40. Triangle, Incenter, Excenter. Level: High School, SAT Prep, College
In triangle ABC, the angles A and B measure 80 and 40 respectively, I is the incenter and E the excenter. AB and CE meet at D. If BC = a, AC = b and CI = d, prove that ..



###########

[أحمد سعد الدين]

تمرين رقم (229)




##########

[أحمد سعد الدين]

تمرين رقم (230)




##########

[أحمد سعد الدين]

تمرين رقم ( 231 )



###########

[أحمد سعد الدين]

تمرين رقم ( 240 )



##########