Posted by **HELP PLS MARVELOUS** on Wednesday, January 9, 2013 at 8:04am.

ABCD is an inscribed quadrilateral. AD, BC are produced to meet at X. If angle B= 80 degrees and angle X= 30 degrees, find angle XCD.

- GEOMETRY -
**Reiny**, Wednesday, January 9, 2013 at 8:47am
I will assume you mean "inscribed in a circle"

In a cyclic quadrilateral, the opposite angles are supplementary, so angle D = 100°

Also angle ADC is an exterior angle in triangle DCX, so

angle DCX + angle CXD = angle ADC

angle DCX + 30 = 100

angle DCX = 70°

- GEOMETRY -
**Anonymous**, Friday, January 11, 2013 at 1:39am
30

- GEOMETRY -
**Jovan Alvin Tapalla**, Monday, January 13, 2014 at 2:22am
50 degrees

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