10 and 18 I am having trouble with
I don't see a pic for 10 but I'm pretty sure we have an inscribed right angle CMD with C and D being the diameter endpoints....
The diameter length, CD = sqrt ( CM^2 + MD^2) =
sqrt (9^2 + 12^2) =
sqrt (81 + 144) = sqrt (225) = 15
OM will form a radius = (1/2)CD = 7.5
Since LA is perp. to OK and LD is perp. to OM.....angles LAO and LDO are right angles
And since arc KL is congruent to arc ML, then central angle KOL = central angle MOL (central angles intercepting equal arcs are themselves equal)
And by the reflexive property, LO = LO
So.......by AAS.......triangle LAO is congruent to triangle LDO
To post the pic just open the image tab and past the URL in.
It is super easy!