If the side length of a square garden covering 4 hectares is reduced by 10 meters, how many square meters will the area of the garden be reduced

If the side length of a square garden covering 4 hectares is reduced by 10 meters, how many square meters will the area of the garden be reduced

1 ha = 10000 M2
4 ha = 40000 M2 = 200m * 200m
(200-10) * (200-10) = 36100 square meters
40000-36100 = 3900 square meters
The area has been reduced by 3900 square meters

A triangular field, 90 meters long at the bottom and 80 meters high, with a total of 2430 kg of vegetables. How many kg of vegetables per hectare

Analysis: Here we mainly investigate the knowledge points of 1 hectare = 10000 square meters
Field area = 90 * 80 / 2 = 3600 M2 = 0.36 ha
Unit yield = 2430 / 0.36 = 6750 kg / ha

With a 120 meter long fence against a section of wall, a 30 meter high right angle trapezoidal vegetable garden is surrounded. The total yield of this land is 1620 kg. How many thousand vegetables are produced per hectare on average

With a 120 meter long fence against a section of wall, a 30 meter high right angle trapezoidal vegetable garden is surrounded. The total yield of this land is 1620 kg. How many kg of vegetables are produced per hectare on average?
1620÷【（120-30）×30÷2÷10000】
=1620÷【1350÷10000】
=1620÷0.135
=12000kg