Watch the video clip (no sound) to understand the diagram
(i) Since the length of the paper is 30 cm, from the diagram, we note that
Height of letter in terms of x = 30 - x - x cm, which is same as 30 - 2x cm
(ii) Given the ratio Height : Width = 8 : 5
Since we can express the height of the letter in terms of x, we shall try to express the width of the letter in terms of x, too.
Refer to the line (in orange), width = 3 + x cm
Now, with these information, we use the ratio to form the equation and use it to find x:
(iii) To find the perimeter of the letter, we need to find the y (marked out in the diagram)