A letter-shaped girder is a type of structural support used in construction. It is made up of four different types of girders: an I-bar, an H-bar, an H-beam, an I-beam, and a T-beam. An I-bar is a girder with a cross section that is shaped like the letter 'I'. An H-bar is a girder with a cross section that is shaped like the letter 'H'. An H-beam is a girder with a cross section that is shaped like the letter 'H' but with two flanges. An I-beam is a girder with a cross section that is shaped like the letter 'I' but with two flanges. A T-beam is a girder with a cross section that is shaped like the letter 'T'.