A trapezoidal wheat field, 17.4 meters, 4 meters, the area is 391 square meters, its bottom is how many meters? One more by the way The floor of a house is paved with square bricks. 270 square bricks with a side length of 0.4 meters are needed. How many square bricks do you need if you use square bricks with a side length of 0.3 meters instead? I'll finish the answer tomorrow, otherwise I won't give any points

A trapezoidal wheat field, 17.4 meters, 4 meters, the area is 391 square meters, its bottom is how many meters? One more by the way The floor of a house is paved with square bricks. 270 square bricks with a side length of 0.4 meters are needed. How many square bricks do you need if you use square bricks with a side length of 0.3 meters instead? I'll finish the answer tomorrow, otherwise I won't give any points

391*2/18.4=42.5
42.5-17.4=25.1
0.4*0.4*270/0.3/0.3=480

A trapezoidal wheat field, the area is 540 square meters, 20 meters at the top and how many meters at the bottom
Use equation to solve (more detailed) QAQ

After autumn and rainy season,
Let the bottom be x meters
（18＋X）×20÷2＝540
18＋X＝540÷10
X＝54－18
X＝36

A trapezoidal wheat field is 6 meters long at the top, 9 meters long at the bottom and 25 meters high. How many square meters is the area of this wheat field

[(6+9)×25]/2=187.5