The figure below shows ray FA and two lines that intersect at point F. What is the measure of DFC? A. 110° B. 125° C. 145° D. 160°
To find the measure of angle DFC, we need to consider the angles that are formed when a transversal crosses two parallel lines. In this case, lines DF and AC are parallel because they are alternate interior angles with respect to the transversal FA.
Since angle DFA is 70° (as given) and angle AFC is 90° (as shown in the figure), angle DFC can be calculated by subtracting the sum of angles DFA and AFC from 180° (because they are supplementary):
DFC = 180° - (70° + 90°)
DFC = 180° - 160°
DFC = 20°
Therefore, the measure of angle DFC is 20°, which is not one of the given answer choices.