1. If AB and BC are sides of a triangle,which angle is the included angle of these two sides
a. angle A
b. angle B
c. angle C
d. angle
2. which of these statements is always true
a. the diameter of a circle is a chord
b. the chord of a circle is a diameter
c. the raidus of a circle is half of a chord
d. a chord passes thru the center of the circle​