∠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).