The author shares a story of how Luis González, an iron artisan, helped the author build a wooden and iron toy truck. The knowledge required to build the skeleton for the parallelepiped in the construction of the truck is not in the mathematical high school curriculum in Venezuela. Although Luis never received a degree beyond high school, mathematics was encoded in the "know-how". Ethnomathematics is a research field where the cultural relativism of mathematics is stressed. This article presents a mathematical exploration in order to unfreeze mathematics. The problem in the activity is to construct a right parallelepiped from sticks using any method. The activity suggests tasks that can be used following the examination of students' answers.