Final answer:
To determine the height of the stamp, we apply the 30°-60°-90° triangle properties and find that the height is 20√3 mm, which is approximately 34.64 mm.
Step-by-step explanation:
The student's question relates to applying the properties of a 30°-60°-90° right triangle to find the height of an object, in this case, a stamp from the Netherlands. Given that the length of each side of the stamp is 40 millimeters and assuming the stamp is square, to find the height, we utilize the knowledge that in a 30°-60°-90° triangle, the side opposite the 30° angle is half the length of the hypotenuse, and the side opposite the 60° angle (the height we want to find) is √3/2 times the length of the side opposite the 30° angle.
Let's assume the length of the side of the stamp is the hypotenuse. Then the side opposite the 30° angle is 20 mm (half of the hypotenuse), and the height (opposite the 60° angle) is √3/2 times 20 mm, which is 20√3 mm or approximately 34.64 mm.