In a physics lab, Ray Zuvlite arranges two mirrors with a right angle orientation as shown. Ray then directs a laser line at one of the mirrors. The light reflects off both mirrors as shown. If angle A is 25°, determine the what is the angle measure of angles B, C, and D?

B = 25°

C = 65°

D = 25°

Explanation:

The given parameters are;

The orientation of the two mirrors = At right angle to each other

The laser light is directed at one of the mirror

The measure of angle, A = 25°

The measures of angle B, C, and D are found as follows;

We have;

∠A = ∠B = 25°, by angle of incidence equals angle of reflection

∠B = 25°

∠B + ∠C = 90° by sum of the acute angles of a right triangle

25° + ∠C = 90°

∴ ∠C = 90° - 25° = 65°

∠C = 65°

∠E = ∠C = 65° by angle of incidence equals angle of reflection

∴ ∠E = 65°

Line 'L' is perpendicular to the second mirror, therefore, the angle between line 'L' and the second mirror = 90° = ∠E + ∠D

∠E + ∠D = 90°,  by angle sum property

Therefore;

65° + ∠D = 90°

∴ ∠D = 90° - 65° = 25°

∠D = 25°