Correct Answer: Option D

Explanation

Using Pythagoras theorem

⇒ \((20\sqrt2)2 = x^2 + x^2\)

⇒ 800 = \(2x^2\)

⇒ 400 = \(x^2\)

⇒ x = \(\sqrt400\) = 20 cm

∴ Area of a square = \(x^2 = 20^2 = 400 cm^2\)

∴ Perimeter of a square = 4x = 4 x 20 = 80 cm

There is an explanation video available below.

• What is the quadrant when x-4 is divided by x²+3x-8? Answer this

  1 Answers   ·   Mathematics   ·   1 hour ago
• how to write a semi formal letter? Answer this

  1 Answers   ·   English Language   ·   5 hours ago
• What is the probability that pupil ohosen at random will pass the rest if the pass mark is :? Answer this

  1 Answers   ·   Mathematics   ·   5 hours ago