Answer:
AD and BE is perpendicular => angle BED = 90 deg.
Otherwise angle CED = arc CD = 30 deg
=> angle BEC = angle BED - angle CED = 90 - 30 = 60 deg
Suppose a, b and c are 3 sides of a triangle in which a < b < c.
As property of length of sides a, b, and c of a triangle:
c - b < a < c + b
b - a < c < b + a
c - a < b < c + a
=> 6.7 inches, 1.1 inches, and 7.9 inches are not sides of a triangle
Check:
7.9 - 1.1 < 6.7 <=> 6.8 < 6.7 <=> invalid!
Hope this helps!
:)
