The exact value of y is
.
Solution:
The attached below shows how the formula is written.
Using geometric mean,
Total base length (p + q) = 8
q = 6
p = 8 – 6 = 2
Let us first find the height of the triangle.



Taking square root on both sides,

Using Pythagoras theorem,
<em>In right triangle, square of the hypotenuse is equal to the sum of the squares of the other two sides.</em>




The exact value of y is
.