triangle problem

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Answer is 90 Choice E

by suragga » Thu Dec 25, 2008 6:46 pm
Angle ADB and Angle ADC are supplementary i.e.

Angle ADB + Angle ADC =180
Angle ADB +60 =180
Angle ADB = 120

Sum of internal angles for a triangle ABD is 180.
On this basis Angle DAB = 180 -120 - 45 = 15

As line segment CD is twice of line segment DB. Angle CAD is 30.

Sum of internal angles for a triangle ACD is 180.

Angle ACD (x) = 180 - 60 - 30 = 90.

Answer is 90.

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Re: Answer is 90 Choice E

by tritrantran » Thu Dec 25, 2008 7:44 pm
suragga wrote:

As line segment CD is twice of line segment DB. Angle CAD is 30.
How did you get this?