Here is my friendly solution i'll skip the proof part for now. I am working on the others.
Answer:
x = 10
Step-by-step explanation:
l n 20 + l n 5 = 2 l n x
ln (20×5) = ln x²
ln(100) = lnx²
100 = x²
x = +/- 10
Since logs of negative numebrs don't exist, we reject -10
we are given with a triangle with the sides 6 ft, 21 ft, 23 ft. although it follows the rule of triangles that state that no side of the triangle exceeds the sum of the lengths of two other sides, this does not follow Pythagorean theorem: 23^2-21^2 = 88 which is not equal to 6^2 or 36. This is not a right triangle, hence. Hope this helps!
Answer is 0.89 sorry for bad drawing and putting 89 as the answer instead of 0.89