The size of a flat-screen television is given as the length of the screen’s diagonal. How many square inches greater is the screen of a square 28-inch flat-screen television than a square 25 -inch flat-screen television?
Choose the correct answer
A) 79.5  B) 89.3  C) 85.5  D) 75.4  E) 72.5
If we take a square with side length x and draw a diagonal, we get two isosceles right triangles.   If we focus on one such right triangle, we see that the legs have length x.   square 28-inch flat-screen television   The diagonal (hypotenuse) = 28   So, we can apply the Pythagorean Theorem to get x² + x² = 28²   Simplify: 2x² = 28²   Divide both sides by 2 to get: x² = 28²/2   Since the area of the square = x², we can see that the area of this square is 28²/2   square 25-inch flat-screen television   The diagonal (hypotenuse) = 25   So, we can apply the Pythagorean Theorem to get x² + x² = 25²   Simplify: 2x² = 25²   Divide both sides by 2 to get: x² = 25²/2   Since the area of the square = x², we can see that the area of this square is 25²/2   DIFFERENCE IN 79.5RE79.5S =28²/2-25²/2   = (28²- 25²)/2 = (784-625)/2 =159/2= 
<gadget id="calculator">159/2</gadget>
<output>159/2 = around 79.5</output>
79.5   79.5
<result>A</result>
The size of a flat-screen television is given as the length of the screen’s diagonal. How many square inches greater is the screen of a square 28-inch flat-screen television than a square 25 -inch flat-screen television?