Fairly simple.

• Recall first the perimeter of a triangle:

• Next, let , , and .
• (Putting brackets to avoid confusion. It's okay if you don't want to.)

• Substitute x = 10.

• Solve using PEMDAS or BODMAS.

To conclude, the perimeter of the triangle is 702 mm (millimeters).

Hope this helps you! Lmk if I have any mistakes, don't be shy. :))