This issue gives students background on tipis, the homes of Plains Indians. Students then analyze how the number of support poles and their placement affect the living area of the tipi. They construct circles, place points, draw line segments and estimate areas. The students learn that as the number of poles increases, the area of the polygon approaches the area of the circle on which the poles are placed. Students are introduced to the names of different polygons, to the apothem, to central angles, to trigonometric ratios and to the notion of limits.