Write the order of following length in metres :
Radius of earth.

What is the length of the radius of the earth?

Write the order of frequency range of the following. Ultra violet rays

If arc length of a sector is l and radius of the circle is r. Write the relation among area of the sector A, radius (r) and arc length (l).

Express the following statements by equations : The perimeter of a rectangle is 40 metres and its length exceeds 5 times of its breadth by 2 metres.

Give the relation between focal length and radius of curvature of a spherical mirror.

If the perpendicular distance from the centroid of an equilateral triangle to one of its sides is 'a' find the length of the radius of the inscribed circle

If the perpendicular distance from the centroid of an equilateral triangle to one of its sides is 'a' find the length of the radius of the circumscribed circle.