help me finish this pythagorean theorem model problem I can't understand it

Let's rotate and redraw the figure to make it easier to understand:
The figure appears to be a right triangle with its hypotenuse and opposite side given.
Since this is a right triangle, to be able to get the measurement of the adjacent side, we will be using the Pythagorean Theorem:
[tex]a^2+b^2=c^2[/tex]The formula for the adjacent side or c is:
[tex]a^2+b^2=c^2[/tex][tex]b^2=c^2-a^2[/tex]Let's now plug in the given values to get b.
[tex]b^2=c^2-a^2[/tex]Given: c² = 225 and a² = 145
[tex]b^2=225\text{ - 145}[/tex][tex]b^2=80[/tex][tex]b\text{ = }\sqrt[]{80}\text{ = }\sqrt[]{16\text{ x 5}}\text{ = 4}\sqrt[]{5}[/tex]