Answer:The answer is 1 and 3
Step-by-step explanation:
The angles of a triangle add to 180 degrees so the remaining angle must be 90°.
This triangle is half a square. It's one of the two tired triangles of trig, the other being half an equilateral triangle, 30°/60°/90°.
48 mm long
Since a square has all equal sides, it will be 12mm for all sides
Perimeter = L (Length) + W (Width) + L + W
(In this case since it’s a 2D shape)
12 + 12 + 12 + 12 = 48
Hope this helped :)
The answer would be 42.875