The shawl starts from the tip. Strictly speaking, it is not a triangle because the upper side is a bow. The fabric is rather dence and heavy, hence the name Raske punane, which means “Heavy red”. The sides are 75 cm long and the distance from the tip to the middle of the bow is also 75 cm. More pictures in my blog.
The pattern available in Finnish from Moda 2010/6.