Okie, hope you a new year!
The below solved example problem may be useful to understand how the values are being used in the mathematical formulas to find the triangle area. Find the area of a triangle having the base b = 18 & height h = 12 cm?
2(5+ square root of 8)
=2(5+2.8284271247)
=2(7.8284271247)
=15.656854249
Square root of
15.656854249
=3.9568743029