Which method is used in the modern era to measure the distance of a nearby planet from the Earth?

When the planet Jupiter is at a distance of $824.7 \; \text{million km}$ from the Earth, its angular diameter is measured to be $35.72''$ of arc. Calculate the diameter of Jupiter.

$A$ $LASER$ is a source of very intense,monochromatic,and unidirectional beam of light. These properties of a laser light can be exploited to measure long distances. The distance of the Moon from the Earth has been already determined very precisely using a laser as a source of light. $A$ laser light beamed at the Moon takes $2.56 \; s$ to return after reflection at the Moon's surface. How much is the radius of the lunar orbit around the Earth?

What is meant by the angular diameter of the moon?

$A$ man wishes to estimate the distance of a nearby tower from him. He stands at a point $A$ in front of the tower $C$ and spots a very distant object $O$ in line with $AC$. He then walks perpendicular to $AC$ up to $B$,a distance of $100 \; m$,and looks at $O$ and $C$ again. Since $O$ is very distant,the direction $BO$ is practically the same as $AO$; but he finds the line of sight of $C$ shifted from the original line of sight by an angle $\theta = 40^{\circ}$ ($\theta$ is known as 'parallax'). Estimate the distance (in $m$) of the tower $C$ from his original position $A$.

The distance of the Sun from the Earth is $1.496 \times 10^{11} \ m$ and the diameter of the Sun is $1.393 \times 10^9 \ m$. Find the angular diameter of the Sun in radians.