Abstract
Since 1994, Home Economics has been become compulsory for boys at Senior High School. However, within the field of Home Economics, only about 6 or 10 hours per year are allotted to "Homes and lifestyles". Therefore, it is difficult to engage the interest of students. The writer proposes changing of the teaching style from a conventional class to a practical lesson in which students make their own designs. The teaching material is "a practical lesson in spatial understanding using a triangular plan".