a. In the diagram above, PQSR and SRYZ are parallelograms, and PQYZ is a straight line. If |QY| = 2cm and |RS| = 3cm, find |PZ|

b. P and Q are two towns on the Earth's surface on latitude of 56°N. Their longitudes are 25°E and 95°E, respectively. Find the distance PQ along their parallel of latitude, correct to the nearest km. [Take radius of the earth as 6400 km and π = \(\frac{22}{7}\)]