Question

what should be the minimum height of man as shown in the figure so that he may see of image of S in the mirror

Answer 1

The first thing to understand is that objects and their images on either side of a mirror are arranged in perfect symmetry:

That means the object and the image are exactly the same distance from the mirror, or the mirror is exactly half the distance between image and object.

Now consider a person as the object, looking at an image of himself or herself. To see the top of his image, the mirror needs to at least reach the line from his eyes to the top of his image. That’s one line of sight. Similarly, to see the bottom of his image, the mirror needs to reach at least the line from his eyes to the bottom of the image. That’s another line of sight Together with the height of the image, these two lines of sight form a triangle:

Since the mirror is exactly half the distance between object and image, then the triangle formed by the mirror and the two lines of sight must be half the size - the mirror must be half the height of the person.

Answer 2

Answer:140 cm

Explanation:

We simply need to find y to calculate the height of the man.

We can find it using similar triangles or using trigonometry.

See the attachment below the first method is using similar triangles and the next one below it is using trigonometry.

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Hope it helps!!