Question

The diagram below shows a ray of light being reflected off a plane mirror. The normal

is shown by the dotted line.

There are some angles below marked in grey. Which one of them correctly shows the

angle of incidence?(Support your answer with reason)​

Answer 1

Answer:

Explanation:

(i)

Let the measure of the complementary angle be a.

40 + a = 90

∴ a = 50°

Hence, the measure of the complement of an angle of measure 40° is 50°

(ii)

Let the measure of the complementary angle be a.

63 + a = 90

∴ a = 27°

Hence, the measure of the complement of an angle of measure 63° is 27°

(iii)

Let the measure of the complementary angle be a.

45 + a = 90

∴ a = 45°

Hence, the measure of the complement of an angle of measure 45° is 45°

(iv)

Let the measure of the complementary angle be a.

55 + a = 90

∴ a = 35°

Hence, the measure of the complement of an angle of measure 55° is 35°

(v)

Let the measure of the complementary angle be a.

20 + a = 90

∴ a = 70°

Hence, the measure of the complement of an angle of measure 20° is 70°

(vi)

Let the measure of the complementary angle be a.

90 + a = 90

∴ a = 0°

Hence, the measure of the complement of an angle of measure 00° is 0°

(vii)

Let the measure of the complementary angle be a.

x + a = 90

∴ a = (90 − x)°

Hence, the measure of the complement of an angle of measure x° is (90 − x)°

Answer 2

Answer:

The measure of the angle is 90 - x

Hope the answer helps you