ANGLE STRAIN!!!
Geometry
Level
3
GIVEN A QUADRILATERAL ABCD WITH AD=AB=5 cm. ANGLE DAB=140 DEG & ANGLE BCD=110 DEG. FIND THE LENGTH OF AC IN cm.
The answer is 5.
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1 solution
since angle DAB=140 therefore reflex ANGLE DAB is 360-140, i.e =220 and since angle BCD =110 i.e half of reflex angle DAB. now we know the property of circle i.e angle subtended at the center is twice that of at arc. so draw a circle passing through the vertex B,C & D making a as the center , therefore AB=AC=AD=5 cm