Me with a problem of derive the formula for area of a triangle

Match the following reasons with the statements given to create the proof. 1. do = ob, ao = oc sas 2. doc = aob given 3. triangle cod congruent to triangle aob vertical angles are equal. 4. 1 = 2, ab = dc if two sides = and ||, then a parallelogram. 5. ab||dc if alternate interior angles =, then lines parallel. 6. abcd is a parallelogram cpcte

Atransformation was performed on rectangle c as shown in the graph. what type of transformation was performed? does that transformation result in congruent shapes? you people

How do you figure out which order to do two step equations in? like which thing do you subtract/add/multiply/divide first? i understand that you do the opposite of whatever's shown on the opposite side, but when?