-2b(-7)=11 =============
2 answers:
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Area = π × r2. Or, when you know the Diameter: A = (π/4) × D2. So A = 6π, which is 18.85. So A = 18.85. And here's the hand.
The 2 angles are complemantary or form right angles so 
so
. Plugging that into BDC we get 11
The first picture shows solution for a. For b). X=9,2
