Margie and Tommy were instructed by mechanical teachers equipped with large screens that displayed lessons and posed questions. The children received their education through computer and television screens, devoid of human teachers.
Margie and Tommy had mechanical teachers, computers, and telebooks for their studies. Their school didn't have its own building. The mechanical teachers displayed lessons and tests on a big screen and could quickly grade assignments. Students were limited to study rooms and received mechanical instruction.
In Fig. 9.26, A, B, C and D are four points on a circle. AC and BD intersect at a point E such that ∠ BEC = 130° and ∠ ECD = 20°. Find ∠ BAC.