9.99 > 9.9 > 9.09

9.99 is greater than 9.9 because 9.99 is greater than 9.9 by 0.09

Step-by-step explanation:

See attachment below

An obtuse triangle has a obtuse angle that measures larger than 90 degrees.

You have to apply the Phytagorean Teorem, which is:

c^2 = a^2 + b^2

c=√(a^2 + b^2)

"c" is the hypotenuse.

"a" and "b" are the legs of the triangle (10 inches and 15 inches).

Let's substitute those values in the equation:

c=√(a^2 + b^2)

c=√(10^2 + 15^2)

c=√325

c=18 inches

What is the smallest possible whole-number length of the unknown side?

** **

It is the next largest integer greater: 19 inches.