a) value of x:
ZX =(10x+9)°
122°=( 10x+9)
122 - 9= 10x
113= 10x
x = 113/10= 11.3 °
so answer is = 11.3°
b) measure of Arc XZ :
formula to find Arc= © angle÷360 x 2πr
A = 122÷360 x 2πr
A = 61/180x 2πr
A = 0.3388x2πr
A= 0.6776πr
Answer: a.11.3° b.i have no idea
