Math
posted by Syed .
If the bisector of the vertical angle of the triangle bisects the base prove that the triangle is isosceles?

Math 
drwls
The law of sines says that the ratio of the common bisector line to the sine of the unbisected side angles must be the same. Therefore the two side angles must be equal. That makes the triangle isosceles.
Respond to this Question
Similar Questions

corollary to isosceles triangle theorem
how to prove 1)the measure of each angle of an equilateral triangle is 60. 2)the bisector of the vertex angle of an isosceles triangle is the perpendicular bisector of the base. Thanks. 1) The angles in any triangle have to add up … 
geometry
I have triangle XYZ with BX as the bisector sides XY and XZ are congruent. I have to write a proof for angle Y being congruent to angle Z. This is what I have, but it doesn't seem correct  can anyone help? 
MathCHECK PLEASE
Which of the statements is ALWAYS TRUE? AA right triangle is a scalene triangle. BAn equilateral triangle is an isosceles triangle. CAn isosceles triangle is an obtuse triangle. DA right triangle is an acute triangle. I got either 
Calculus
Show by vector calculation that the bisector of the angle between the two equal sides of an isosceles triangle bisects the third side and is perpendicular to it. 
SAT math
Can someone please double check my true and false answers! 1. All cylinders are prisms: TRUE 2. The angle opposite a side length of 6 cm in a triangle is larger than an angle opposite a side length of 7 cm in the same triangle: FALSE … 
geometry
I need to figure out this proof, the figure is two triangles forming a rhombus. Given: segment BD is the angle bisector of triangle ABC and triangle ADC Prove: Triangle ABD is congruent to Triangle CBD So far I have segment BD is the … 
maths
Abc is a triangle where ad bisects angle a and d is the midpoint of bc prove that triangle is isosceles 
Math
Answer with Always, Sometimes or Never True. Kindly explain why so that I can understand. Thanks. 1. An interior angle and an exterior angle of a triangle are supplementary. 2. The bisector of an angle of an isosceles triangle is also … 
Math
If the ratio of a base angle and vertical angle of an isosceles triangle is 1:2 find the angles of the triangle 
Math
Show that the bisector of the vertical angle of an isosceles triangle bisect the base at right angles