(2004? The cross section of Shaoxing's round vegetable greenhouse is as shown in the figure, AB=8m, ∠ CAD = 30, then the greenhouse height CD is about () A.2.0mB.2 。
According to OC⊥AB, then ad = 12ab = 4m.
At the right angle △ACD, ∠ CAD = 30, then CD=AD? tan30 =433≈2.3m
Then the greenhouse height CD is about 2.3 m.
So choose B.