X = 13.26
here’s a photo with the work if that helps at all :)
SA= Lateral Area + Area (of base)
Lateral area = perimeter of base x height
An isosceles triangle has two congruent base segments. The hypotenuse of an isosceles right triangle is (length of base segment) x (the square root of 2). I did the math for you (shown above) to get 5 as a base.
So 5 + 5 + square root of 50 is your perimeter
Multiply the perimeter times your height (8) and you get the lateral area.
Add your lateral area to the base area (triangle = 1/2 bh)
LA = 136.568...
Area of Triangle base = 12.5
Surface area = 149.068... square cm
Hi friend,
((5+a)/a)/((a^2 -25) /5a)
=(a+5)/((a^2 - 25)/5)
=(a+5)(5)/(a+5)(a-5)
=5/(a-5)
Therefore your answer is B)
Hope this helps you!