How do i find the perimeter and area?

To find the perimeter, just add up all the sides. 3+4+5=12m. The perimeter is 12 meters.

To find the area, multiply the base times height and multiply by 1/2. 3x4=12. 12*1/2=6. The area of this right triangle is 6m^2. (The ^2 is squared or to the second power).
I hope this helps! :)