question 20 (a) the size of a television is given as the length of the diagonal of the screen
The tv has a size of 42"
The height of the tv is 20.4"
what is the width of the screen?

A2 + C2 = B 2
422+ 20.42 =C2
42 X 42 = 1764
20.4 x 20.4 = 416.16
1764 - 416.16 = 1347.84
√1347.84 =36.7
C = 36.7 inchs