How to describe the dimention of rectangle paint on wall

[aumijia]

I need to describe the dimention of rectangle paint on wall both in English and in Chinese, this is what I write:

Pain a red rectangle on the wall, make sure the width is 10cm and the height is 5cm.
在墙上画一个红色的长方形，确保它的长(Length)是10厘米，宽(Width)是5厘米。

I didn't pay too much attention for the different between two languages and just translate the Width(English) to Length(Chinese) and then Height(English) to Width(Chinese).

My question is: Will this be treated as translation error and will this make any different if this translation occurs in a formal contract.

I really appreciate if some one can help me to find the answer. Thanks a lot.