Because it says that BE is a diameter, and that the distance around half of the circle is 180 degrees, you can set 7x+ 5x+12=180, so you know that 12x equals 168. So, x equals 14. 5 times 14 is 70, plus 12 is 82. Subtract 82 from 180, to get 98. Divide that by2 to get 49, because those two arcs are congruent. Because central angles are congruent to the measures of the arcs that they intersect, the answer is 49 degrees.
