Answer:
28.4cm
Step-by-step explanation:
Perimeter of the wall will be the sum if all the sides of the right angled triangle.
Given the height of the triangle = 6cm
Hypotenuse = 12cm
Using Pythagoras theorem to get the third side
Hypotenuse² = opposite²+adjacent²
Taking the height as the opposite = 6cm
12² = 6²+adj²
Adj² = 12²-6²
Adj² = 144-36
Adj² = 108
Adj = √108
Adj = 10.39cm
The perimeter of the wall = 6cm+12cm+10.39cm
= 28.39cm
= 28.4cm to nearest tenth.