We know that the length of the inradius of a right-angled triangle is given by the formula (a+b-h)/2 , where aa and bb are the lengths of the arms of the triangle and hh is the length of the hypotenuse of the triangle.
Also, we know that the length of the circumradius of a right-angled triangle is h/2.
Circumradius of a triangle is always greater than its inradius.
Squaring on both sides, we get,
We know that in a right-angled triangle, a
2 + b
2 = h
2.
Substituting in (1), we get,
We know that the area of the triangle is ab/2.
Area of the square = h
2.
Ratio of the areas of the triangle and the square
Therefore, option D is the right answer.
Alternate solution:
Let 'R' be the circumradius of the triangle and 'r' be the inradius.
For a right-angled triangle, area = r(r+2R)
It has been given that difference between the lengths of circumradius and inradius is equal to one-fourth the hypotenuse of the triangle.
Hypotenuse = 2*circumradius
⇒ R - r = R/2
R = 2r
Area of the triangle = r(r + 2 * 2r)= 5r
2Area of the square = (2R)
2 = (2*2r)
2 = 16r
2Therefore, the required ratio is 5:16.