What? what is the question?
Side-Side-Side Theorem, Side-Angle-Side, Angle-Angle-Side, Angle-Side-Angle, and Hypotenuse-Leg for right triangles.
For example, for Side-Side-Side, if you prove all 3 sides of the triangle are congruent, then the triangle is congruent.
Let the length of maria's book be a and that of Brandon's be b.
So, by the question,
the difference in length of books is 56
i.e. a-b=56------(1)
and the length of books all together is 348
i.e. a+b=348------(2)
Adding (1) and (2);
(a-b)+(a+b)=56+348
or, a-b+a+b=404
or, 2a=404
or, a=202
substitutting the value of a in (2),
202+b=348
or, b=146
therefore, the length of Maria's book is 202
and the length of Brandon's book is 146.
