arc Z = 100°
arc Y = 80° x 2 = 160°
arc Z = (360° - 160°)/2 = 100° because the 2 chords are of equal length, then arc Z = the arc opposite Z
answer rather than having to add and subtract the measurements of the semi-circle, notice that the semicircle to the left of ad is actually identical in area to the blank semicircle-shaped space to the left of bc. so if we transferred the red semicircle into the blank space, we would end up with a square of side length 24 cm. the area of a square is s^2 = 24^2 = 676 cm^2.
u also answered this so i think u would know but i am here to
put in or use mine
only 10/60 isn't equivalent
hope this : )