Final answer:
To attain a 30° reclining angle for a lawn chair, the manufacturer cuts notches, ensuring ∠B=60°. Subtracting 30° from the right angle of 90° accommodates the chair's tilt, achieving a comfortable and stable reclining position through practical design adjustments.
Step-by-step explanation:
In order for the reclining lawn chair to be reclined at an angle of 30°, the manufacturer needs to cut notches on the back of the chair. To find the measure of ∠B, we need to subtract 30° from 90° since the angle formed between the back of the chair and the ground is a right angle. So ∠B = 90° - 30° = 60°. By subtracting the reclining angle from the right angle, the manufacturer ensures that the chair provides both comfort and structural support. This design approach, involving the subtraction of angles, is a practical and effective means of achieving the desired reclining angle of 30° while maintaining the chair's overall stability.