The three sides of a triangle are in different colors – blue, green and red. The ratio of the length of the blue side to the length of the green side to the length of the red side is 3 : 4 : 5. The perimeter of the triangle is 240 cm. a) Fill in the blank: ___ units = 240 cm b) Fill in the blank: 1 unit = ___ cm c) What is the length of the red side of the triangle?