Question

Big Vain monster is 16 feet tall an eye at 10 feet in the middle of his 6 feet wide body. What size (both directions)of a mirror and where should it be placed for Big Vain to fully see his self?

(a) Rule(s)

(b) What the rule(s) says

(c) This problems application of that or

those rules.

Answer 1

Rule: The length of mirror needed to see the whole object is half of the length of the object. This also means that to observe the image above or below the eye level, the length of mirror needed is also half of the length of object above or below the eye levels respectively.

Now, since monster is 16 feet tall and has eyes at 10 feet from ground, so his head is 6 feet high above the eyes level and his feet are 10 feet below the eye level.

By applying the above rule, mirror needed above eye level is 3 feet and below eye level is 5 feet with total mirror length is 8 feet. Similarly, the eye is in middle of the body which is 6 feet wide, so mirror needed is 1.5 feet on each side from the middle of the body, i.e 3 feet in total width.