grade 10, angle problem (geometry). 1. The problem statement, all variables and given/known data find values of angles a, b and c in order http://img151.imageshack.us/img151/4662/trigproblemyn1.th.jpg [Broken] the two lines withthe arrows drawn on them are parallel the center is at where the 94 degree angle forms 2. Relevant equations none side note though: this is from a text book for grade 10 students in a section under the angluar rules (like in the diagram, you can tell that angle b and angle c are the same because those two lines are parallel) 3. The attempt at a solution okay, i tried but i didnt get too far because i kept sending myself into loops and winding where everything cancelled out to be something like 180 = 180. i based my work off of the general rules for working with angles: a + b + 94 = 180 a = 86 - b b = c from there i tried extending the line from a through the center (which is at the 94 degree angle) and intersecting it with the parallel line coming from the angle c. i got an equation for that but it was the exact same as the very first equation i had so subbing in b = c, gave me no values for any of the angles. then from the extended line i reied looking at the quadraliteral formed and using the "all interior angles in a quaderalideral sum to give 360" rule but that gave me the sum of: [180 - b] + c + [180 - 94] + 94 = 360 (angles reading left to right) but subbing in b = c, again cancelled out all the variables leaving me with no answer once more. i tried drawing a third chord (from a across to the other side of the line coming from angle c) to form a triangle but that led me nowhere also. i think im thinking too deeply into to, it might not need the that much thought, but i cant see it any other way. (i even tried drawing in a line to half the "a b 94" triangle, it didnt work either) im actually a little depressed now, because my little sister was the one who asked me to help her with that problem >< and i couldnt do it, now i have to ask for help *sigh* i've been looking at it for ages now but i cant see how its possible to find the angles with only that much information. there may be a rule for it but i couldnt find one in the text book and there were no answers because it was a challenge problem. if anyone could help me out here i would really appreciate it. thanks in advance.