measure of arc DEF
Check the final answer first, then review the worked steps.
Problem
measure of arc DEF
Step-by-step solution
The inscribed angle subtended by arc DF is 78 degrees. The measure of arc DF is twice the inscribed angle, so arc DF = 2 * 78 = 156 degrees. The full circle is 360 degrees. The measure of arc DEF is the measure of the major arc DF, which is 360 - 156 = 204 degrees.
Answer
$204^{\circ}$