Angle Bisector Theorem - Triangle
Angle Bisector Theorem 内角の二等分線定量
Use the applet below to complete this activity.
a) Make an internal angle bisector 内角の二等分線 for angle A.
b) Find the point of intersection 交点 between the angle bisector and BC.
c) Name the point of intersection D.
d) Find the lengths長さ: AB, BD, AC, CD
Calculate the ratios and . What do you notice? Change the triangle by moving the vertices and calculate again. とは、比を計算しなさい。どのようなことがわかりますか？ 頂点を動かして三角形を変え、もう一度計算してみましょう。
Calculate the ratios and . What do you notice? Change the triangle and calculate again.
External Angle Bisector Theorem 外角の二等分線定量
Use the applet below to complete this activity.
a) Make an external angle bisector 外角の二等分線 for angle A.
b) Find the point of intersection 交点 between the angle bisector and the line through BC.
c) Name the point of intersection D.
d) Find the lengths長さ: AB, BD, AC, CD
Calculate the ratios and . What do you notice? Change the triangle by moving the vertices and calculate again. とは、比を計算しなさい。どのようなことがわかりますか？ 頂点を動かして三角形を変え、もう一度計算してみましょう。
Angle Bisector Theorem (Interior and Exterior)
In triangle ABC with angle bisector AD, AB:AC=BD:DC