Does anyone know how the three squares are filled? I do not know what it means what I marked in blue

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

Need 50 will mark brainliest answer. find the lengths of all the sides and the measures of the angles.

When are triangles considered similar? a. corresponding angles are equal andcorresponding sides are proportionalb. corresponding angles are proportional andcorresponding sides are equalc. corresponding angles are equal orcorresponding sides are proportionald. corresponding angles are proportional orcorresponding sides are equal select the best answer from the choices providedmark this and retumsave and exitnext