Answer:
9%
Explanation:
Original rectangle: 100 cm by 200 cm
Original area: 100 cm * 200 cm = 20,000 cm^2
Reduced by 70%, the measures are now 30% of they they were.
30% of 100 cm = 30 cm
30% of 200 cm = 60 cm
New area: 30 cm * 60 cm = 1800 cm^3
New area equals what percent of original area?
1800/20,000 * 100 = 9%