Answer: the dimensions of the triangle are 29 feet, 58 feet and 59 feet.
Step-by-step explanation:
Let x represent the length of the shortest side.
Let y represent the length of the medium side.
Let z represent the length of the longest side(third).
One side twice the length of the shortest side. It means that
y = 2x
The third side is 30 feet more than the length of the shortest side.. This means that
z = x + 30
if the triangle's perimeter is 146 feet units, it means that
x + y + z = 146- - - - - - -- - - - -1
Substituting z = x + 30 and y = 2x into equation 1, it becomes
x + 2x + x + 30 = 146
4x = 146 - 30
4x = 116
x = 116/4
x = 29 feet
y = 2x = 2 × 29
y = 58 feet
z = x + 30 = 29 + 30
z = 59