Question

Ina∆ABC,if AB=ACandla =70,findlb and lc

Answer 1

Given: ∆ABC AB=AC and angle a =70
To Find: angle c and b
If Ab=ac then ∆abc is an issoceles ∆
and in a issoceles ∆ the angles on the two equal sides are equal
therefore, angle b = angle c = x
by angle sum property of a ∆
a +b+c=180
70 + x+ x=180
2x=180-70
x=110÷2
x=55
ans Angle b = angle c = 55°