Step-by-step explanation:
about circle R
arc angle MP = angle MRP = 78°
angle M = angle LMP.
according to the rules of inscribed angles, LMP is half of angle LRP.
LRP + MRP = 180° because together they cover the whole LM segment (half-circle).
LRP = 180 - MRP = 180 - 78 = 102°
so, LMP = angle M = 102/2 = 61°
also circle R (with arc ULNP)
the arc ULNP = arc UL + arc LN + arc NP = 160°
due to the congruent definition of JU and MP we know that arc UL = arc NP.
and we know arc LN = arc JM = 18°.
so,
160 = 2×arc NP + 18
142 = 2×arc NP
arc NP = 71° = arc UL
now, because arc MP + arc LP = 180 (half-circle),
arc MP = 180 - arc LP = 180 - arc LN - arc NP =
= 180 - 18 - 71 = 91°
about the circle R with 2 congruent chords :
the second answer : they are equidistant from R (the center of the circle).
about circle W
arc MK + arc KL = 180° (half-circle).
and we see
arc HL = arc KL = 53°.
so,
arc MK + 53 = 180°
arc MK = 180 - 53 = 127°
about circle M
arc QTS = 204°.
therefore, arc QRS = 360 - arc QTS = 360 - 204 =
= 156° = angle QMS.
according to the rules of inscribed angles
angle QTS = QMS/2 = 156/2 = 78°
be the cylindrical region, then
denotes the unit normal vector to 
, but we don't need to worry about it now)
