As you may have noticed, in the United States, roof slope is usually expressed as x:12. The slope should always be noted in elevation and section views; it is optional to note it in plan view. In plan view, it is a simple open arrow indicating the slope's direction. The angle of the arrow is proportional to the degree of slope. In this article, we will discuss how to show roof slope on a building plan or other plan view drawing. First, find the highest point on the roof. Usually, this is either at the peak of the roof or in the middle between the peaks. You can use any horizontal line as a reference for the height of the building. Now draw a vertical line from one end of the building to the other. This will form two angles with the ground. If you were to connect each corner of the building to its corresponding corner on the vertical line, these lines would form a diamond pattern. Each angle of the diamond is 90 degrees. They intersect at the highest point on the roof. Now that you know where to find the highest point on the roof, you can indicate the slope of the roof by using an angled arrow. The longer the arrow, the steeper the slope. Use a meter stick or ruler to ensure that you create an accurate representation of the roof slope. You can also express the slope of the roof in degrees.