Question

What is the length of the diagonal of a rectangle whose width is 90 cm and whose length is 200 cm? (Round your answer to the nearest whole centimeter.)

Answer 1

Answer: the answer is c.

Step-by-step explanation: Let W, L and D = the width, length and diagonal of the rectangle, respectively.  

Then, by the Pythagorean theorem,  

W^2 + L^2 = D^2

<=>

D = sqrt(W^2 + L^2)

= sqrt(90^2 + 200^2)

= sqrt(48100)

= 10 sqrt(481)

None of the choices offers an exact solution. However, an approximate solution is:  

10 sqrt(481) ≈ 219.317,  

which rounds to 219, so the closest answer is C.