A lizard needs to stay a safe distance from a cactus. The diameter of the cactus is 12 inches. If the lizard is 8 inches from a point of tangency, find the direct distance between the lizard and the cactus (x). If necessary, round to the hundredths place.

1 answer

To find the direct distance between the lizard and the cactus (x), let’s first establish the relationship between the lizard’s position, the cactus's position, and the point of tangency.

  1. Understand the Geometry:

    • The cactus has a diameter of 12 inches, which gives it a radius (r) of: \[ r = \frac{diameter}{2} = \frac{12 \text{ inches}}{2} = 6 \text{ inches} \]
    • The distance from the point of tangency on the cactus to the lizard is given as 8 inches.
  2. Setting Up the Relationship:

    • Let (C) be the center of the cactus and (T) be the point of tangency. The radius (CT) from the center to the point of tangency is 6 inches.
    • Let (L) be the location of the lizard. The distance from the lizard to the point of tangency (T) is given as 8 inches.
  3. Applying the Pythagorean Theorem:

    • The direct distance (x) from the lizard (L) to the center of the cactus (C) can be visualized as a right triangle formed by the following points:
      • From the center of the cactus (C) to the point of tangency (T) as one leg (which is the radius = 6 inches).
      • From the point of tangency (T) to the lizard (L) as the other leg (8 inches).
    • The direct distance (x) from the lizard (L) to the center (C) is the hypotenuse.

Using the Pythagorean theorem:

\[ x^2 = CT^2 + TL^2 \]

Substituting the known values:

\[ x^2 = 6^2 + 8^2 \] \[ x^2 = 36 + 64 \] \[ x^2 = 100 \]

Thus,

\[ x = \sqrt{100} = 10 \text{ inches} \]

  1. Conclusion: The direct distance between the lizard and the cactus is \( \boxed{10} \) inches.