Blood Type Compatibility. Your ABO blood type is based on the presence or absence of the A and B antigens on your red blood cells. The A blood type has only the A antigen and the B blood type has only the B antigen. The AB blood type has both A and B antigens, and the O blood type has neither A nor B antigen.
Green Triangle. The green triangle appears in the upper left hand corner of a cell when there is an error in a formula. Sometimes Excel will report an error when you use text in a box and the program believes it is part of a formula. When you click on the green triangle there will be a yellow box that looks like a road sign with an exclamation point in it. This button is the Trace Error option that will help you correct your formula.
Step 3. Click the View tab on the upper side of the Excel window. Step 4. If in Normal View mode, click Page Layout on the upper left, below the tabs, to switch to Page Layout view; this will allow you to see the numbers on screen. Step 5. Click the Insert tab on the upper left side of the Excel window.