In triangle ABC, points D, E, F are on sides BC, CA, AB respectively such that AD, BE, CF are concurrent. If BD:DC = 2:3, CE:EA = 3:4, find AF:FB using Ceva's theorem.

Answer: The ratio AF:FB is 2:1.

Step-by-step solution

Step 1: State Ceva's Theorem

Ceva's Theorem states that for a triangle ABC, if points D, E, F are on sides BC, CA, AB respectively, then the lines AD, BE, CF are concurrent if and only if the product of the ratios of the segments on each side is equal to 1. This theorem provides a powerful tool for solving problems involving concurrent lines in a triangle.

Step 2: Substitute Given Ratios

We are given the ratios BD:DC=2:3BD:DC = 2:3 and CE:EA=3:4CE:EA = 3:4. We substitute these values into Ceva's Theorem. The ratio BD:DCBD:DC can be written as BDDC=23\frac{BD}{DC} = \frac{2}{3}, and CE:EACE:EA as CEEA=34\frac{CE}{EA} = \frac{3}{4}.

Step 3: Simplify the Equation

Now, we simplify the product of the known ratios. Multiply the numerators and denominators: 2⋅3=62 \cdot 3 = 6 and 3⋅4=123 \cdot 4 = 12. This gives us 612\frac{6}{12}, which simplifies to 12\frac{1}{2}.

Step 4: Solve for AF:FB

To find the ratio AF:FBAF:FB, we isolate it by dividing both sides of the equation by 12\frac{1}{2}. Dividing by a fraction is equivalent to multiplying by its reciprocal. Therefore, 1÷12=1⋅2=21 \div \frac{1}{2} = 1 \cdot 2 = 2.

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