That is incorrect. That problem involved algebra and geometry. The shape is an equilateral triangle, so the two sides are equal. Build an algebraic equation and solve for x to find the answer. According to your answer, we recommend starting with Volume 4 of the Learn Math Fast System. That book will teach you all about triangles, plus a whole lot more geometry.
RESULTS: The end of 8th Grade Level, however, the Learn Math Fast System is for all ages. Volume 4 covers 3rd - 8th grade geometry topics, but there is no mention of grade level within the books.