help me with perimeter and area of polygons and train

In this case the answer is very simple.
To find the solution to the exercise we'll have to carry out several steps.
Step 01:
Data:
side = 12 in
hypotenuse = 13 in
Step 02:
Pythagoras Theorem
h² = a² + b²
13² = 12² + b²
[tex]\begin{gathered} b\text{ = }\sqrt[]{13^{2}\text{ -12² }} \\ b\text{ = }\sqrt[]{169-144}\text{ = }\sqrt[]{25} \\ b\text{ = 5 in} \end{gathered}[/tex]Step 03:
Area
A = (b * h) / 2
[tex]A\text{ = }\frac{5\cdot12}{2}=\text{ }\frac{60}{2}=30in^2[/tex]Step 04:
Perimeter
P = a + b + h
P = 12 + 5 + 13 = 30 in
The solution is:
Area A = 30 in²
Perimeter P = 30 in