勾股定理c2 = a2 + b2
面积a × b / 2
c边的高 (h)a × b / c
a边角平分线2 × b × c × Cos(A/2) / (b + c)
b边角平分线2 × a × c × Cos(B/2) / (a + c)
c边角平分线 (tc)tc2 = 2 × a2 × b2 / (a + b)2
a边中位线 ( ma )ma2 = b2 + 0.25 × a2
b边中位线 ( mb )mb2 = a2 + 0.25 × b2
c 边中位线( mc )mc = c / 2
内切圆半径a × b / ( a + b + c )
外接圆半径c / 2