Question

By what theorem or postulate can you determine the value of x?

Answer 1

Answer:

Triangle Proportionality Theorem.

Step-by-step explanation:

See the attached diagram.

Two lines EG and FH are parallel and hence, EG will divide the sides DF and DH in the same ratio as per Triangle Proportionality Theorem.

So, we can write $\frac{DE}{EF} = \frac{DG}{GH}$

⇒ $\frac{3}{4.1} = \frac{2.3}{x}$

⇒ x = 3.14 cm. (Answer)