Question

What is the measure of ∠CEF?

A. 80 degrees
B. 90 degrees
C. 100 degrees
D. 110 degrees

Answer 1

D. 110

Explanation:

30+40=70

180-70=110

Answer 2

∠CEF = 110°

Explanation:

ΔBED ,

∠BED + ∠BDE + ∠DBE = 180 {Angle sum property}

∠BED + 40 + 30 = 180

∠BED + 70 = 180

∠BED = 180 -70

∠BED = 110°

∠CEF = ∠BED {Vertically opposite angles}

∠CEF = 110°