6.4 Areas of Similar Triangles

Step 1

Using the Area Ratio Theorem: $\frac{\text{Area}(ABC)}{\text{Area}(DEF)} = (\frac{BC}{EF})^2$ .

Step 2

Substitute values: $\frac{64}{121} = (\frac{BC}{15.4})^2$ .

Step 3

Take square root of both sides: $\frac{8}{11} = \frac{BC}{15.4}$ .

Step 4

Solve for BC: $BC = \frac{8 \times 15.4}{11}$ .

Step 5

$15.4 / 11 = 1.4$ . So $BC = 8 \times 1.4 = 11.2$ cm.

Final Answer

11.2 cm

Operation

Angle 1 (degrees)

Select operation and enter angles.