This diploma thesis deals with surface forming methods, especially accuracy and measurement of sheet metal bending on Van Mark brakes. The aim of the work was to make bends of samples in the range of 30 °, 60 °, 90 ° and 120 °. The size of the bend of the examined samples is influenced by the suspension of the sheet, which is not taken into account in the currently used type of protractor. The samples were then analyzed on two types of measuring devices - tactile and optical. After measuring, results were evaluated and plotted in the appropriate graphs. Based on the measurement results, a new type of protractor was designed, which will make the user's work easier and more efficient.