Multiple choice

If the hypotenuse of a right angled triangle is $41\ cm$ and the area of the triangle is $180\ sq.cm$, find the difference between the lengths of the legs of the triangle

  1. $22\ cm$
  2. $25\ cm$
  3. $27\ cm$
  4. $31\ cm$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let legs be a and b. a^2 + b^2 = 41^2 = 1681. Area = 1/2 * ab = 180, so ab = 360. (a-b)^2 = a^2 + b^2 - 2ab = 1681 - 720 = 961. a-b = sqrt(961) = 31.

AI explanation

Let the legs be a and b. The area gives the equation one half of a times b equals 180, so a times b equals 360. Pythagoras theorem gives a squared plus b squared equals 41 squared, which is 1681. The difference between the legs squared is (a squared plus b squared) minus 2ab, calculated as 1681 minus 720, which equals 961. Taking the square root of 961 gives the difference between the legs as 31 cm.