Advertisements
Advertisements
प्रश्न
Bisectors of the angles B and C of an isosceles triangle with AB = AC intersect each other at O. BO is produced to a point M. Prove that ∠MOC = ∠ABC.
Advertisements
उत्तर
Given in the question, bisectors of the angles B and C of an isosceles triangle ABC with AB = AC intersect each other at O. Now BO is produced to a point M.

In triangle ABC,
AB = AC
∠ABC = ∠ACB ...[Angle opposite to equal sides of a triangle are equal]
`1/2 ∠ABC = 1/2 ∠ACB`
That is ∠1 = ∠2 ...[Since, BO and CO are bisectors of ∠B and ∠C]
In triangle OBC,
Exterior ∠MOC = ∠1 + ∠2 ...[Exterior angle of a triangle is equal to the sum of interior opposite angles]
Exterior ∠MOC = 2∠1 ...[∠1 = ∠2]
Hence, ∠MOC = ∠ABC.
APPEARS IN
संबंधित प्रश्न
Can a triangle have two acute angles?Justify your answer in case.
Compute the value of x in the following figure:

Fill in the blank to make the following statement true:
A triangle cannot have more than ...... right angles.
In a Δ ABC, the internal bisectors of ∠B and ∠C meet at P and the external bisectors of ∠B and ∠C meet at Q, Prove that ∠BPC + ∠BQC = 180°.
In the following, find the marked unknown angle:

The length of the sides of the triangle is given. Say what types of triangles they are 4.3 cm, 4.3 cm, 4.3 cm.
D is any point on side AC of a ∆ABC with AB = AC. Show that CD < BD.
In the following figure, AB = BC and AD = BD = DC. The number of isosceles triangles in the figure is ______.

What is common in the following figure?
![]() |
![]() |
| (i) | (ii) |
Is figure (i) that of triangle? if not, why?
Can we have two acute angles whose sum is a reflex angle? Why or why not?


