BD is tangent to circle O at C, m(arc AEC) = 280, and m(arc ACE) = 140. Find m (The figure is not drawn to scale.)

Answer:
The correct answer is second option 60°
Step-by-step explanation:
From the figure we can write,
measure of arc AEC = measure of arc AE + measure of CE
measure of arc ACE = measure of AC + measure of CE
measure of arc AEC + measure of arc ACE = 280 + 140 = 420°
measure of arc AE + measure of CE + measure of AC + measure of CE = 420
measure of arc AE + measure of CE + measure of AC = 360°
measure of CE = 420 - 360 = 60°
The correct answer is second option 60°