Answer:
Set 4: 12 ft, 16 ft, 20 ft
Step-by-step explanation:
A right angle triangle is a triangle in which one of the angles is a right angle (i.e 90°). The side opposite to the right angle is the longest side and is called the hypotenuse. The Pythagoras theorem for a right angle triangle states the the square of the hypotenuse is equal to the sum of the square of the remaining two sides.
For set 1:
4² + 5² = 16 + 25 = 41
6² = 36
6² ≠ 4² + 5²
It does not form a right triangle
For set 2:
8² + 12² = 64 + 144 = 208
20² = 400
20² ≠ 8² + 12²
It does not form a right triangle
For set 3:
10² + 20² = 100 + 400 = 500
30² = 900
30² ≠ 10² + 20²
It does not form a right triangle
For set 3:
12² + 16² = 144 + 256 = 400
20² = 400
20² = 12² + 16²
It forms a right triangle