First, read the English article below.

Sugar maple leaves will have a dark green color on the outside, and a lighter green on the underside. In the fall, sugar maple leaves will lose their green color and take on a beautiful orange, yellow, or red. Sugar maple leaves are segmented into 5 lobes. There should be three large, main lobes and one smaller lobe on either side.  The lobes are characterized by sharp teeth, and are connected by shallow, U-shaped notches.  Some underdeveloped or stunted sugar maple leaves will have only three or four lobes. If you see a leaf with fewer than five lobes but suspect the tree is a sugar maple, look around and find other leaves, which may be better specimens. The leaves of the Silver maple (Acer saccharinum) can be distinguished from those of the Sugar maple. Silver maple leaves have very deep margins between the five lobes, and the underside is silver or white in color. Sugar maple leaves have smooth, U-shaped margins between points. The leaves should also be round at the base.  While many other maples also have smooth margins, the extremely common red maple (Acer rubrum) has sharp points and serrated or toothed margins between the lobes. This can be a useful distinguishing feature.  The sugar maple leaf stalk (also called a “petiole”), which connects the individual leaves to the branch they grow on, should be the same length as (or slightly shorter than) the blades of the leaves. Look for leaves that grow perpendicular, or at a right angle, from the twig, in pairs. This is called an opposite orientation. Leaves will grow in “sets” of two, with one leaf always across from another on every twig and branch. Only one leaf should grow from each individual stem. Mature leaves on a sugar maple average between 3 inches (7.72 cm) and 5 inches (12.7 cm) long, and are equally as wide. If you won’t have a ruler with you in the woods, but are planning to examine tree leaves, measure a segment of one of your fingers. This can serve as an approximate ruler in the field. For example, from the tip of your thumb to the first... 

Now, please write a short abstract for it in Vietnamese. Abstract:
Quan sát kỹ màu sắc của lá. Đếm các thùy lá. Xem xét mép lá cây. Kiểm tra kiểu mọc của lá trên nhánh lá. Đo kích thước lá. Tìm ba đường gân chính trên lá cây.