Answer:
- height: 9 chi 6 cun
- width: 2 chi 8 cun
Step-by-step explanation:
The factor-of-ten relationship between the different units means we can combine the numbers in decimal fashion. If 1 unit is 1 zhang, then 1 chi is 0.1 zhang and 1 cun is 0.01 zhang. Hence 6 chi 8 cun is 0.68 zhang.
Let x and y represent the width and height, respectively. In terms of zhang, we have ...
y - x = 0.68
x^2 +y^2 = 1^2
Substituting y = 0.68 +x into the second equation gives ...
x^2 + (x +0.68)^2 = 1
2x^2 +1.36x - 0.5376 = 0 . . . . . eliminate parentheses, subtract 1
Using the quadratic formula, we have ...
x = (-1.36 ±√(1.36^2 -4(2)(-0.5376)))/(2·2) = (-1.36 ±√6.1504)/4
x = 0.28 . . . . . the negative root is of no interest
y = 0.28 +0.68 = 0.96
In units of chi and cun, the dimensions are ...
height: 9 chi 6 cun
width: 2 chi 8 cun
