Question

In the adjoining figure, IBC and AB and AC are the
transversals. If 22 - 23 and 21 = = 22,
then the measure of ZB is
(a) 80°
(b) 70
(c) 72°
(d) 76
Bc​

Answer 1

Answer:

80

Step-by-step explanation:

lets take

angle 2=x

angle 3=x

now, angle 1=x÷4

as we know angle (1+2+3)=180

x+x+(x÷4)=180

2x+x÷4=180

(8x+x)÷4=180

9x÷4=180

9x=180×4

x=720÷9

x=80

angle 2=angle b

so, angle b=80