Incenter - Jenna Means
几何画板及绘图内容加载中,请稍等……
① This example demonstrates the construction of the incenter of a triangle and its associated angle bisectors, perpendicular segments, and angle labels in GeoGebra. ② Core mathematical concepts include the definition of the incenter as the intersection of internal angle bisectors, properties of angle bisectors, the inradius (distance from incenter to sides), and angle measurement. ③ Construction details: the Polygon command creates triangle ABC; AngularBisector constructs the three internal angle bisectors; Intersect finds their common point D (the incenter); Angle labels angles α, β, etc.; Segment connects vertices to the incenter; OrthogonalLine draws perpendiculars from the incenter to sides, revealing the inradius; text objects annotate the figure. ④ Suitable for middle school to high school students learning triangle centers, angle bisector theorems, and geometric construction, as well as for classroom demonstrations by teachers.
GeoGebra 命令及参数
Polygon(A, B, C) → poly1, c, a, bAngularBisector(A, C, B) → fAngularBisector(C, B, A) → gAngularBisector(B, A, C) → hIntersect(f, g) → DAngle(poly1) → α, β, γAngle(D, A, C) → δAngle(B, A, D) → εAngle(D, B, A) → ζAngle(C, B, D) → ηAngle(D, C, B) → θAngle(A, C, D) → ιSegment(D, A) → iSegment(D, C) → jSegment(D, B) → kOrthogonalLine(D, c) → lOrthogonalLine(D, b) → mOrthogonalLine(D, a) → nIntersect(l, c) → EIntersect(n, a) → FIntersect(m, b) → GSegment(D, E) → pSegment(D, F) → qSegment(D, G) → r