Point 9 of 9 — Unit 3: Parallel Lines, Proportional Segments and Angle BisectorsQuestion bank: 0 questions (0 with pictures)
093-9 Mixed applications with areas
Triangles ABD and ACD share the same altitude from A, so area(△ABD)/area(△ACD) = BD/DC; using the bisector theorem this ratio is also AB/AC.
Combining with similarity: a ratio of lengths gives a ratio of areas only when the triangles are similar or share an altitude — state which one you are using.
Perimeter problems: if a bisector or a parallel divides a side, first find the two parts with the ratio, then substitute into the length formulas.
Coordinate setups: assign the base on the x-axis and use the section formula with the ratio from the bisector theorem to locate D.
📝 Question bank for this point
0 questions linked to this point only, 0 of them with pictures.