<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">geometric models</topic></authority><related type="broader"><topic>instructional models</topic></related><variant type="other"><topic>geometric model</topic></variant> <note xml:lang="en"><![CDATA[ Three-dimensional polyhedra meant to illustrate or demonstrate mathematical or geometric principles, or as models for drawing exercises. These are normally in sets containing various solids such as cones, spheres, cubes, cylinders, triangular pyramids, etc. ]]></note></mads>