Complete angle

A ray of light incident on the horizontal surface of a glass slab at 70^@ just grazes the adjacent vertical surface after refraction. Complete the critical angle and refractive index of glass.

If x^(@) is the measure of an angle which is equal to its completment and y^(@) is the measure of an angle which is equal to its supplement, then find (x^(@))/(y^(@))

In the figure , angle LMN = angle LKN = 90^(@) seg MK bot seg LN . Complete the following activtiy to prove R is the midpoint of seg MK .

In the table given below, dimensions and angles of various crystals are given. Complete the table by filling the blanks.

Given : square ABCD is cyclic. /_DCE is an exterior angle of square ABCD. To Prove : /_DCE = /_BAD Complete the proof by filling the boxes.

In the table given below, dimensions and angles of various crystals are given . Complete the table by filling the blanks.

Statement-I: In a clock,minutes hand completes one rotation in one hour and hours hand completes one rotation in 12 hours. Statement II: Angles can be classified into various types based on the amount of rotation made by the terminal side with respect to initial side of an angle.

A plane is going in circles around an airport. The plane takes 3 minutes to complete one round. The angle of elevation of the plane from a point P on the ground at time t seconds is equal to that at time (t + 30) seconds. At time (t + x) seconds, the plane mes vertically above the point P. What is x equal to ?