Final answer:
To find uncle spider's height off the ground, use similar triangles and set up a proportion to solve for the unknown height. Mama spider's height off the ground and the distances to the mirror can be used to establish this proportion.
Step-by-step explanation:
To find uncle spider's height off the ground, we can use the concept of similar triangles. Since Mama spider can see uncle spider in the mirror, the line connecting the two spiders is perpendicular to the mirror's surface. This creates two similar triangles: the triangle formed by Mama spider, uncle spider, and the mirror, and the triangle formed by the reflection of uncle spider, the mirror, and the ground.
Let's assume the height of uncle spider off the ground is 'x'. Since Mama spider is 72 inches off the ground and the mirror is 10 inches from Mama spider, the height of Mama spider off the ground is 72 + 10 = 82 inches. Similarly, since uncle spider is 5 inches from the mirror, the height of uncle spider off the ground is x + 5 inches.
Using the concept of similar triangles, we can set up the following proportion:
(x + 5)/x = 82/10
Cross-multiplying and solving the equation, we can find the value of x, which represents uncle spider's height off the ground.