Quick questions on Latitude, longitude and angular distance for HSC Maths Standard 2

Latitude is the angle, measured at the centre of Earth, between a point and the equator. The equator is the great circle halfway between the poles, and it is latitude $0^\circ$. Moving towards the North Pole the latitude increases to $90^\circ$ N; moving towards the South Pole it increases to $90^\circ$ S. Lines of equal latitude are the parallels - circles running east to west, parallel to the equator.

Longitude is the angle, measured at the centre of Earth, between a point's meridian and the Greenwich meridian. A meridian is a half great-circle running pole to pole; the one through Greenwich in London is the prime meridian, longitude $0^\circ$. From there longitude is measured up to $180^\circ$ E (eastward) and $180^\circ$ W (westward), meeting at the $180^\circ$ meridian on the far side of Earth. Australia is east of Greenwich, so its longitudes are E: Perth is near $116^\circ$ E and Sydney near $151^\circ$ E.

A point is written with latitude first and longitude second, each with its label: