1, trapezoidal wheat field, 400 meters above the bottom, 500 meters below the bottom, and 100 meters high. How many hectares is it? If you harvest 7000 kilograms of wheat in one hectare, can you harvest 60 tons in this wheat field?

Solution: area = 0.5 * (400+500) *100m2 = 45,000m2 = 4.5 hectares.

The wheat actually received is 4.5 * 7000kg = 31500kg = 31.5t.

2. Xiao Ming walked five times around a square, and one * * walked10000m. What is the area of this square?

Solution: side length 10000/5/4m = 500m, area 500 * 500 = 250000m2.

Pyramid of khufu is the largest pyramid in history, covering an area of about 5.29 hectares (52,900 square meters).

4. 1900 square kilometers or 20 hectares?

Solution: 1900 km2 =19000000 m2 > 20 hectares = 200,000 m2.

Therefore, 1900 square kilometers is large.

5.228,000 square meters =( 22.8) hectares