Grades 9-10 Video Solutions 2025-2025_9-10

Video Transcription

Video Summary

The problem involves finding the area of triangle ALJ in a larger triangle ABC with given conditions. Triangle ABC has an area of 60, while point I is the midpoint of BC, and points J and K divide AC into three equal parts. By comparing triangles and using their geometric properties, specifically the fact that they have the same heights and equal bases, the triangles ALJ, JLK, and KLC are shown to have equal areas, denoted as X. By setting up equations with known areas of AIC and BJC in terms of X and Y, and solving them, the area of triangle ALJ is determined to be 5.

Keywords

triangle area

geometric properties

midpoint

equal parts

area calculation