Help me please help mee

7.5

Step-by-step explanation:add all sides and then divide by 4

Step-by-step explanation:

Help you do what exactly?

Maybe prove that this is not really a valid triangle?

Easily done if we ASSUME that dimension 5 and 4 are valid, the third side of that triangle would be √(5² - 4²) = 3

Which means the other triangle would have legs of 9 and 12 - 3 = 9 making it an equilateral triangle not a right triangle.

If we assume sides 12 and height 4 are correct, then

A = ½(12)(4) = 24 units²

If we ASSUME that the outside legs are true, the the true height can be found using

√(5² - h²) + √(9² - h²) = 12

which resolves to about

h = 3.399

The area would be

A = ½(12)(3.399) = 20.394 units²

A VERRRY confusing question.