Which of the following shows two congruent triangles

Find the gradient of f(x, y,z)equals=left parenthesis x squared plus y squared plus z squared right parenthesis superscript negative 1 divided by 2 baseline plus ln left parenthesis x right parenthesis x2+y2+z2−1/2+ln(xyz) at the point left parenthesis negative 2 comma 1 comma negative 2 right parenthesis(−2,1,−2).

In the diagram, the ratio of ab to ae is (1/2) . what is the ratio of the length of to the length of ?

How do i do this activity, is appreciated