Question

class 10th...Triangles chapter
ans this​

Answer 1

b) 4

I hope it helps u dear friend ☺

Answer 2

Answer:

• 4 cm is the value of x.

Step-by-step explanation:

In the figure,

• DE║BC

We know,

• AD/DB = AE/EC

[∵ Basic proportionality theorem]

Substituting the values

⇒ (x)/(x - 2) = (x + 2)/(x - 1)

⇒ x(x - 1) = (x - 2)(x + 2)

⇒ x² - x = x² - 2²

⇒ x² - x = x² - 4

⇒ x - 4 = 0

⇒ x = 4

∴ The value of x is 4.

Basic proportionality theorem:

A line drawn parallel to one side of a triangle divides the other two sides proportionally.

In ΔABC, if DE║BC, then ΔADE ~ ΔABC.

∴ AD/AB = AE/AC = DE/BC.