Final answer:
To find the length of AC in the triangle ACB, we can use the Pythagorean Theorem. The length of AC is approximately 12.33.
Step-by-step explanation:
To find the length of AC in the triangle ACB, we can use the Pythagorean Theorem. According to the theorem, in a right triangle, the square of the length of the hypotenuse (AC) is equal to the sum of the squares of the lengths of the other two sides (AB and BC).
Using the given information, we have:
AB = 21, CD = 8, and CB = 17
Let's call the length of AC 'x'.
By applying the Pythagorean Theorem, we get:
x^2 = 21^2 - 17^2
x^2 = 441 - 289
x^2 = 152
x = sqrt(152)
x ≈ 12.33
Therefore, the length of AC is approximately 12.33.