Question

How is the answer 7? someone help i need this urgently ​

Answer 1

     The 20 represents the specific section, the 8 adds onto that side making the full side 8.

-> See attached

Using this, we can set up a proportion to solve;

     Sides of the smaller triangle are on the top, and sides of the larger triangle are on the bottom

[Proportion we made]

$\frac{20}{28}=\frac{5}{x}$

[Cross-multiply]

20x = 140

[Divide both sides of the equation by 20]

x = 7 ✓

This is how they reached 7, I hope this answer explains it so you can understand.

Have a nice day!

     I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly.

- Heather