The level of the surface of oceans or seas is called the sea level. Land and hills are raised and are at some height from the sea level. City A is $10 \mathrm{m}$ below sea level, City B is $28 \mathrm{m}$ below sea level and City C is $14 \mathrm{m}$ above sea level.

Which of the three cities is at the highest elevation from the sea level?

A truss is a structural framework of wood or metal arranged in a pattern which is used to support roofs or bridges. The structure of a truss made of iron rods is shown in the figure below.

The rods $EF, DG, AH, IK$ and $JL$ are perpendicular to the base $BC$. A number of triangles are formed by the rods.

In the triangle $ABC$, side $AB = AC$. In the triangle $AGK$, all sides are equal and $H$ is the mid-point of $GK$.

Is $AH$ the perpendicular bisector of line segment $GK$? Justify your answer

The figure shows the position of the satellite above earth. PR is the line joining the satellite and the centre of earth. P is the position of the satellite, Q is a point on the surface of earth and R is the centre of earth.

The distance between P and Q is $1300 \mathrm{km}$ and the distance between the centre of earth and the satellite is $7671 \mathrm{km}$.

Shobhit marks Q as zero and the direction from Q to P is positive. What is the distance of R with reference to P?