What is the a + bi form

In two or more complete sentences describe how to determine the appropriate model for the set of data, (1,1), (3,2), (6,3), (11,4).

11. minitab software was used to find the lsrl for a study between x=age and y=days after arthroscopic shoulder surgery until an athlete could return to their sport. use the output to determine the prediction model and correlation between these two variables. predictor coef se coef t p constant -5.054 4.355 -1.16 0.279 age 0.2715 0.1427 1.9 0.094 r-sq = 31.16%

State if the two triangles are congruent. if they are, state how you know?