Answer:
150 units (Option C)
Explanation:
Perimeter of rectangle = Perimeter of triangle
= {2 × (Length + Width)} = Sum of all three sides
= {2 × [(2x) + (x + 12)]} = [(4x) + (2x) + (x + 3)]
The parenthesis are expanded using the Distributive Law:
= {2 × [2x + x + 12]} = [4x + 2x + x + 3]
= {2 × [3x + 12]} = [7x + 3]
= 6x + 24 = 7x + 3
Bring all the like terms together and isolate x:
= 24 - 3 = 7x - 6x
= 21 = x
∴x = 21
Substitute this calculated value of x to determine the perimeter of rectangle:
6x + 24
= 6(21) + 24
= 126 + 24
= 150 units
∴Option C