Question

Find the measure of angle DEF.

https://courseplayer.avalearning.com/CourseFiles/Questions/413176/13%2002.png


A.)39º
B.)78º
C.)58º
D.)29º

Answer 1

DEF is an inscribed angle, because it is composed of two pair of chords, and inscribed angles are calculated by the formula:
\[<ABC = \frac{ arc.AC }{ 2 }\]
Wich will mean, if we apply it to the problem:
\[<DEF=\frac{ arc.DF }{ 2 }\]
\[<DEF= \frac{ 78 }{ 2 }\]

Answer 2

Thank you!

Answer 3

no problem!