ABCD is a cyclic quadrilateral such that when sides AB and DC are produced, they meet at E, and sides AD and BC meet at F, when produced. If $$\angle$$ADE = 80$$^\circ$$ and $$\angle$$AED = 50$$^\circ$$, then what is the measure of $$\angle$$AFB?
From triangle AED,
$$\angle$$ADE +Â $$\angle$$AED +Â $$\angle$$DAE =Â 180$$^\circ$$
80$$^\circ$$ +Â 50$$^\circ$$ +Â $$\angle$$DAE =Â 180$$^\circ$$
$$\angle$$DAE =Â 50$$^\circ$$
ABCD is a cyclic quadrilateral.
Opposite angles in a cyclic quadrilateral is supplementary.
$$\angle$$ADC +Â $$\angle$$ABC =Â 180$$^\circ$$
80$$^\circ$$ +Â $$\angle$$ABC =Â 180$$^\circ$$
$$\angle$$ABC =Â 100$$^\circ$$
From triangle ABF,
$$\angle$$ABF + $$\angle$$AFB + $$\angle$$BAF = 180$$^\circ$$
100$$^\circ$$ + $$\angle$$AFB + 50$$^\circ$$Â = 180$$^\circ$$
$$\angle$$AFB = 30$$^\circ$$
Hence, the correct answer is Option D
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