At a special angle known as Brewster's angle, no p-polarized light is reflected from the surface, thus all reflected light must be s-polarized, with an electric field perpendicular to the plane of incidence. A simple linear polarizer can be made by tilting a stack of glass plates at Brewster's angle to the beam.
In this particular instance, we would start off by measuring the wound in the length dimension. Where there is the maximum length of this wound of approximately 5.7 centimeters. The width would then be measured at its maximum point of width which is 2.5 centimeters. The depth we then would determine by probing the wound with our cotton-tipped applicator using the cotton end.
Measure length first at the longest section then width at the widest section then depth at the deepest section. To measure depth gently insert a cotton swab and were your fingers meet the edge of the wound measure that area on the cotton swab. If depth can't be measured but the wound is open then mark it as <0.1 cm. This tells the next person measuring that is is superficial. To check for tunneling take the cotton swab and gently run it along the inside of the wound edge, if tunneling is found measure like you did the depth.