Advertisements
Advertisements
प्रश्न
ABC is a triangle in which ∠A — 72°, the internal bisectors of angles B and C meet in O.
Find the magnitude of ∠BOC.
Advertisements
उत्तर
Given,
ABC is a triangle
`∠ A=72^@` and internal bisector of angles B and C meeting O
In` Δ ABC = ∠ A+∠ B+∠ C=180^@`
⇒`72^@+∠ B+∠ C=180^@`
⇒`∠ B+∠C =180^@-72^@ ` divide both sides by ‘2’
⇒`∠ B/2+∠ C/2=108^@/2` ..................(1)
⇒`∠ OBC +∠ OCB =54^@` ...................(1)
Now in `Δ BOC⇒ ∠OBC +∠ OCB +∠ BOC = 180^@`
⇒ `54^@+∠BOC=180^@`
⇒ `∠BOC=180^@-54^@=126^@`
∴` ∠ BOC=126^@`
APPEARS IN
संबंधित प्रश्न
In a ΔABC, if ∠A = 55°, ∠B = 40°, find ∠C.
In the given figure, AB || DE. Find ∠ACD.

Is the following statement true and false :
A triangle can have at most one obtuse angles.
Is the following statement true and false :
An exterior angle of a triangle is less than either of its interior opposite angles.
In ΔABC, ∠B = ∠C and ray AX bisects the exterior angle ∠DAC. If ∠DAX = 70°, then ∠ACB =
Find the value of the angle in the given figure:

In the following, find the marked unknown angle:

In ∆ABC, C = 56° C = 56° ∠B = ∠C and ∠A = 100° ; find ∠B.
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.
In the following figure, ∠BAC = 90° and AD ⊥ BC. The number of right triangles in the figure is ______.

