Question

TriangleABC is isoscless with AB=AC,if angleA=80. what is the measure of angle B​

Answer 1

Answer: ∆abc is an isosceles triangle

AB=AC

So,angle ABC=angle ACB [ angles opp to equal sides are equal]

Therefore,

angle A+ angle B+ angle C=180

( angle sum property)

80+x+x=180

2x=180-80

2x=100

x=50

Angle B=50

Answer 2

Answer:

50°

Step-by-step explanation:

In triangle ABC

ANGLE A=80°

AB=AC

ANGLE B=ANGLE =C ( ANGLE OPPOSITE TO EQUAL SIDES ARE EQUAL) -1

So,

ANGLE A + Angle B + Angle C = 180° ( Sum angle property)

80° + 2(Angle B)=180°(Angle B =Angle C from eq. 1)

2(ANGLE )B =180°-80°

ANGLE B = 100°÷2

ANGLE B =50°

..............................

ANGLE B =50°=ANGLE C

Hope it helps.