x = 8
Solution:
Side-splitter theorem:
If a line is parallel to one side of a triangle and the line intersects the other two sides, then this line divides those two sides proportionally.
[tex]$\Rightarrow\frac{4}{21} =\frac{x}{42}[/tex]
Do cross multiplication, we get
⇒ 4 × 42 = 21x
Divide by 21 on both sides, we get
⇒ 4 × 2 = x
⇒ 8 = x
Switch the sides.
⇒ x = 8
The value of x is 8.
