The measure of 3rd side of the triangle rounding to the nearest tenth would be 9.2.
As we can in the figure that the given triangle is a right angle triangle as one of the angle measures 90 degrees.
We are given that one side of it measures 6 and other 7 and we are supposed to find the measure of 3rd side.
Clearly , we can see that the 3rd side is the hypotenuse
So , by using Pythagorean theorem we can find the measure of the 3rd side.
(AC)^2 = AB^2 + BC^2 --- This is what Pythagorean theorem states that the square of hypotenuse is equal to the sum of squares of perpendicular and base.
Let us assume hypotenuse as x
x^2 = 7^2 + 6^2
x^2 = 49 + 36
x^2 = 85
x =

x = 9.21
So the measure of x (hypotenuse ) rounding to nearest tenth would be 9.2 .