一題math help me

a) Let 梯子的頂端與地面的水平的距離是 h
h/5 = cos 20°
h = 4.698m (to 3d.p.) or h = 4.70 (to 3 sig.fig.) (因為唔知答案要幾個位)

b) (h-2)/5 = sinθ
θ = 32.663° (to 3d.p.) or θ = 32.7° (to 3.sig.fig.)

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