AMO 2027 Grades 6-7 SET 10 - Self-study Question 11

Triangle ABC is a right triangle with AB = 60 units, AC = 80 units and BC = 100 units. D is a point between B and C such that △ADB and △ADC have equal perimeters. Find the length of the side BD.

A. 10 units
B. 20 units
C. 40 units
D. 60 units
E. None of the above