Final answer:
To calculate the distance (D) between the compound bends, we use the Pythagorean theorem on one of the right-angled triangles formed by the bend around the obstruction; then, we double the hypotenuse to get the total distance. In this case, the distance is approximately 43.6 inches.
Step-by-step explanation:
To find the distance (D) between the bends of a compound 90° bend using 45° bends to avoid a rectangular obstruction, we can visualize the setup as two right-angled triangles back-to-back. Each triangle will have legs corresponding to the short side (SR) and the long side (LR) of the obstruction. Since SR is 6 inches and LR is 21 inches, we can use the Pythagorean theorem to calculate the hypotenuse of one triangle, which is half of the total distance D needed.
We calculate the hypotenuse (h) of one triangle as:
h = √(SR² + LR²) = √(6² + 21²) = √(36 + 441) = √477
Now, multiplying the hypotenuse of one triangle by 2 to get the combined length for both right-angled triangles that form the compound bend:
D = 2 × h = 2 × √477
When we calculate this, we obtain:
D = 2 × 21.8 (rounded to one decimal place) ≈ 43.6 inches