Answers

2014-08-09T17:50:58+08:00
We first calculate the inside area: 6 cm x 11 cm = 66 cm^2. The total area of the frame is: 28 cm^2 + 66 cm^2 = 74 cm^2. We assume that the Length of the Frame is 11 + 2x, where x is the width of the frame area. And the Width of the frame is 6 + 2x. Now we calculate x first: (11 + 2x)(6 + 2x) = 74 --> 66 + 22x + 12x + x^2 = 74 --> x^2 + 34x - 8 = 0 --> X = 0.2337 and -34.2337. We use 0.2337 since there is no negative width. Width = 6 + 2(0.336) = 6.4674 cm.
0
So we get: 66 + 28 = (6 + 2x)(11 + 2x) --> 94 = 66 + 12x + 22x + 4x^2 --> 4x^2 + 34x - 28 = 0 -->X = 0.7562, -9.2562.
I realized I was wrong earlier. Anyway, to get the L of the Illustration board: 11 + 2(0.7562) = 12.5 cm and W: 6 + 2(0.7562) = 7.5 cm.