word problem

Question

the screen of a 4G ipod has an aspect ratio of 5 to 4. the diagonal measure of the screen is 51.83 millimeters. find the length and width of the screen to the nearest tenth of a millimeter

Answer 1

Let l be length and w be width of the ipod screen

The Aspect Ratio of screen is 5:4. So l:w =5:4

                                                      l/w=5/4

                                                       l = w * 5/4

                                                       l = (5/4) w

Since given diagonal measure of the screen is 51.83 mm

By right angle formula we know, diagonal² = l² + w² 

51.832 ² = (5/4 w)² +  w ²

2686.56 = w² * [(25/16) + 1]

 

2686.56 = w² (41/16) 

2686.56 * (16/14)= w² 

w² = 3070.35

w = √3070.35

width = 55.4 mm

So the width of the screen is 55.4 mm and length, l = (5/4) * 55.4

                                                                  = 69.25 mm