Final answer:
To calculate the volume of the igloo modeled as a hemisphere, the radius was first determined from the given circumference and then the volume formula for a hemisphere [V = (2/3)πr³] was applied, yielding a volume of approximately 77.5 cubic meters.
Step-by-step explanation:
To find the volume of an igloo modeled as a hemisphere, we need to use the information given about the circumference to first determine the radius of the hemisphere. The formula for the circumference (C) of a circle (which applies to our hemisphere's base) is C = 2πr, where π (pi) is approximately 3.14159 and r is the radius.
To isolate the radius (r), we will rearrange the formula to get r = C / (2π). Substituting the given circumference (20.9 m) into the formula gives us r = 20.9 m / (2 × 3.14159), which calculates to approximately 3.33 meters (rounded to two decimal places for intermediate calculations).
After finding the radius, we can calculate the volume (V) of a hemisphere using the formula V = (2/3)πr³. By substituting the radius (3.33 m) into this formula, we find the volume to be about (2/3) × 3.14159 × (3.33 m)³, which equals approximately 77.5 cubic meters when rounded to the nearest tenth.