In the figure, d1 is parallel to d2. What is angle CBA + DEF? A. 225 B. 240 C. 250 D. 260

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1 Answer
Jun 19, 2018

color(maroon)(hat (CBA) + hat (DEF) = 35 + 45 + 180 = 260^@

Explanation:

hat (CBA) = hat (GCB) + hat (CGB), "exterior angle = sum of interior oppo. angles"

Similarly, hat (DEF) = hat (HDE) + hat (DHE)

But hat (CGB) + hat (DHE) = 180^@, " common transversal"

:. hat (CBA) + hat (DEF) = hat (GCB) + hat (HDE) + (hat (CGB) + hat (DHE)

color(maroon)(hat (CBA) + hat (DEF) = 35 + 45 + 180 = 260^@