Lines p and q are parallel. Two distinct transversals r and s intersect p at P and R respectively, and intersect q at Q and S respectively. The transversals meet each other at point O situated between p and q.
At point P the interior angle between p and r is (2x+5)∘, while at point Q the corresponding exterior angle between q and r is 113∘.
At point R the exterior angle between p and s is (3y−7)∘, and at point S the interior angle on the same side of s is 149∘.
a. (a) Find the value of x.
b. (b) Using the obtained value of x, determine the value of y.
c. (c) Hence calculate the acute angle between the two transversals r and s. Explain every step of your working.