FTCE General Knowledge Math Practice Test 2026 - Free Practice Questions and Study Guide

The perimeter of a parallelogram is indeed defined as the sum of the lengths of all its sides. A parallelogram has opposite sides that are equal in length, meaning that if one side is labeled as length \( a \) and the adjacent side as length \( b \), the perimeter can be calculated by adding the lengths of all four sides together: \( a + b + a + b \), which simplifies to \( 2a + 2b \) or \( 2(a + b) \).

This fundamental concept of the perimeter applies universally to all polygons, where you simply add together the lengths of all sides. The other options refer to different geometrical formulas: the formula for area or other calculations, which do not pertain to the perimeter of a parallelogram. Therefore, the correct answer aligns directly with the general definition of perimeter in geometry.