Coefficient is a number next to the variable so the coefficient of this expression is 3/8
<span>Using: a^2 + b^2 = c^2 (pythagoras theorem)
where 'a' and 'b' are the legs of a right triangle, c is the hypotenuse
</span><span>compare the triangle I just drew to the triangle you have for your problem
</span><span>you'll see that a = unknown b = 18 c = 36
</span><span>a=18sqrt3
=31.2</span>