Question

Hey guys can U plz help me out with this one, it is a 'multi answer type question' 'l' is the perpendicular bisector of the side BC of triangle ABC meet the circumcircle of the triangle of M opposite to A then, [ a ] angle MBC = angle MCB [ b ] angle BCM = angle BAM [ c ] angle CMB = angle CAM [ d ] angle BAM = angle CAM

Answer 1

Answer:

The region between a chord and either of its arcs is called a segment the circle.

Angles in the same segment of a circle are equal.

Let bisectors of ∠A  meet the circumcircle of ∆ABC at M.

Join BM & CM

∠MBC = ∠MAC

[Angle in the same segment are equal]

∠BCM = ∠BAM

[Angle in the same segment are equal]

But , ∠BAM= ∠CAM..........(i)

[Since, AM is bisector of  ∠A]

∠MBC= ∠BCM

MB= MC

[SIDE OPPOSITE TO EQUAL ANGLES ARE EQUAL]

So,M must lie on the perpendicular bisector of BC.

Let, M be a point on the perpendicular bisector of BC which lies on circumcircle of ∆ABC. Join AM.

Since, M lies on perpendicular bisector of BC.

BM= CM

∠MBC= ∠MCB

But ∠MBC= ∠MAC

[Angles in same segment are equal]

∠MCB= ∠BAM

[Angles in same segment are equal]

From eq i

∠BAM= ∠CAM

So, AM is the bisector of ∠A

Hence, bisector of ∠A and perpendicular bisector BC intersect at M which lies on the circumcircle of the ∆ABC.