Mathematical problems / volume / ship shape (数学问题/材积/船的形状)

Mathematical problems / volume / ship shape

The grandson who was in elementary school yesterday asked me,
When using wood to build a ship,
What type of boat is the most buoyant and the most material-saving?

1. Rectangle (rectangular)
2. square
3. round
4. 3 angles

I was thinking,
Aren't the ships all rectangular?

I listed the formula

Take the rectangle as an example:
Surface area = wood usage = 2 * (length * width) + (length + width) * 2 * height
Buoyancy to which the ship is subjected = volume of discharged water = length * width * height

Can be seen from the calculation table
round boat is most cost-effective

For rectangular (rectangular) ships, the larger the aspect ratio, the more consumables

So the answer is 3

数学问题/材积/船的形状

昨天读小学的孙子问我，
使用木头来造船的时候，
哪种形状的船，浮力最大又最省材料？
1）长方形（矩形）
2）正方形
3）圆形
4）3角形

当时我想着，
船不就都是长方形的吗？

我把公式列了出来

以长方形（矩形）為例 :
表面积=木材使用量= 2 （长宽）+（长+宽）* 2 高
船所受到的浮力=排开水的体积=长宽*高

从计算表中可看出,
圆形船算划算,
再来是方形船较为划算.

长方形（矩形）的船, 當其长宽比越大，耗材越多

所以答案是3