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A math interest group in a middle school
Solution: (1) In Rt△ABC,

∠BAC=90,∠C=30,

∫tanC = ABAC

∴AB=AC? tanC

= 12×33

=43

≈6.9 meters;

(2) Make an arc with point A as the center and point AB as the radius. When the sunlight is tangent to the arc, the shadow of the tree is the longest.

Point d is the tangent point, and DE⊥AD intersects AC at point e,

In Rt△ADE, ∠ ade = 90, ∠ e = 30,

∴AE=2AD=2×43≈ 13.9 (male). Solution: (1) In Rt△ABC,

∠BAC=90,∠C=30,

∫tanC = ABAC

∴AB=AC? tanC

= 12×33

=43

≈6.9 meters;

(2) Make an arc with point A as the center and point AB as the radius. When the sunlight is tangent to the arc, the shadow of the tree is the longest.

Point d is the tangent point, and DE⊥AD intersects AC at point e,

In Rt△ADE, ∠ ade = 90, ∠ e = 30,

∴AE=2AD=2×43≈ 13.9 (male).