Step-by-step explanation:
we can use o as the center of the circle
OB=13
EB=12
OE=?
OE^2 +EB^2=OB^2
OE^2+12^2=13^2
OE^2=169-144
OE=
√25
OE=5
OC=OE+EC
EC =13-5
EC=8
