三角形面積公式
Author: 藍邦偉　老師

三角形面積公式

Δ= \frac{ 1 }{2 } ah_a= \frac{ 1 }{ 2} absinC

Δ= \frac{ 1 }{ 2}bh_b = \frac{ 1 }{2 }bcsinA

Δ=  \frac{ 1 }{ 2} ch_c=\frac{ 1 }{2 } casinB

A = (8.651949910554562, 4.162754919499106)
B = (4, 0)
C = (10, 0)
多邊形1, c, a, b = Polygon(A, B, C)
d = Circle(A, B, C)
n = 4 (slider from 0 to 4, step 1)
α = Angle(B, A, C)
β = Angle(C, B, A)
γ = Angle(A, C, B)
r = Radius(d)
e = LineBisector(B, C)
f = LineBisector(A, C)
g = OrthogonalLine(A, a)
D = Intersect(g, a)
h = OrthogonalLine(B, b)
E = Intersect(h, b)
i = OrthogonalLine(C, c)
F = Intersect(i, c)
h_a = Segment(A, D)
h_b = Segment(E, B)
h_c = Segment(F, C)
文字2: "= \frac{1}{2} \times{}" + a + "\times{}" + b + "\times{}" + (sin(γ))
文字4: "= \frac{ 1 }{ 2} " + b + "\times{}" + c + "\times{}" + (sin(α))
文字5: "= \frac{ 1 }{2 } \times{}" + c + "\times{}" + a + "\times{}" + (sin(β))
文字9: "=" + (1.0 / 2.0 * a * b * sin(γ))
文字1: "=" + (1.0 / 2.0 * b * c * sin(α))
文字10: "=" + (1.0 / 2.0 * c * a * sin(β))