Pythagorean Theorem: a² + b² = c²
If Triangle A ≅ Triangle B, then hypotenuse length of A would be 9 cm and the another side of triangle A is stay 6 cm.
[tex] {6}^{2} + {x}^{2} = {9}^{2} [/tex]
[tex]36 + {x}^{2} = 81[/tex]
[tex] {x}^{2} = 81 - 36 = 45[/tex]
[tex]45 = 3 \sqrt{5} = x[/tex]
Perimeter of triangle a :
[tex]9 + 6 + 3 \sqrt{5} = 15 + 3 \sqrt{5} [/tex]
Hope this helps ^-^
