I just took the test the answer is 9 cm.
BA and BD are radii of the circle, so triangle ABD is isosceles. Then angles BDA and BAD are congruent, and the remaining (central) angle ABD has measure

Angles ABD and CBD are supplementary, so

and the answer is E.
She would make 3.00 dollars
50(10) - 20(10) = (10)(50 - 20)
500 - 200 = (10 * 30)
300 = 300
(10)(50 - 20) = 30(10)
(10 * 30) = 300
300 = 300
Area=(1/2)bh
given
b=10
h=9
aera=(1/2)9*10=45
3 triangles+base=
45*3+43.3=
135+43.3=
178.3 mm^2