Plane and Solid Angles

The solid angle subtended by a spherical section of an area $3{\mathrm{cm}}^2$ at the centre of curvature situated symmetrically at a distance of $7\mathrm{cm}$ from the area is nearly equal to

The moon's distance from the earth is $3,60,000\mathrm{kms}$ and its diameter subtends an angle of ${31}^{\text{'}}$ at the eye of the observer. Find the diameter of the moon.

One radian is approximately equal to

Conversion of $360°$into radians is:

Convert $18$ degree in to radians.

Which of the following is the correct relation among radians and degrees:

Rewrite the angle $120°$ in radians as a multiple of $\pi$.

Rewrite the angle $\frac{34\mathrm{\pi }}{15}$ in degrees.

Write each of these angles in degrees, correct to $1$ decimal place $1.34$ radians.

Change the angle to degrees: $\frac{3\pi }{10}$

Convert $\frac{\pi }{4}$ radian into degrees.

Name the SI unit of solid angle.

Convert $\frac{\mathrm{\pi }}{4}$radian into degrees.

Solid-angle:

Angle formed at the top of a cone is an example of ‘Plane Angle’.

Which one of the following statements is not true about a plane angle?

${45}^{\circ }$ can be written in radians as

The distance between centres of moon and the earth is about $60$ times the radius of the earth. What will be diameter of the earth (approximately in degrees) as seen from the moon?