MathDB

As shown in the figure below, point

E

lies on the opposite half-plane determined by line

CD

from point

A

so that

\angle CDE = 110^\circ

. Point

F

lies on

\overline{AD}

so that

DE=DF

, and

ABCD

is a square. What is the degree measure of

\angle AFE?

[asy] size(6cm); pair A = (0,10); label("

A

", A, N); pair B = (0,0); label("

B

", B, S); pair C = (10,0); label("

C

", C, S); pair D = (10,10); label("

D

", D, SW); pair EE = (15,11.8); label("

E

", EE, N); pair F = (3,10); label("

F

", F, N); filldraw(D--arc(D,2.5,270,380)--cycle,lightgray); dot(A^^B^^C^^D^^EE^^F); draw(A--B--C--D--cycle); draw(D--EE--F--cycle); label("

110^\circ

", (15,9), SW); [/asy]

<span class='latex-bold'>(A) </span>160\qquad<span class='latex-bold'>(B) </span>164\qquad<span class='latex-bold'>(C) </span>166\qquad<span class='latex-bold'>(D) </span>170\qquad<span class='latex-bold'>(E) </span>174

7