Find the length of each side labeled with the variable give your answer to one decimal place where needed

These are right triangles...so we can use the pythagorean theorem
a^2 + b^2 = c^2where a and b are the legs and c is the hypotenuse.

(a) 3^2 + 7^2 = c^2
      9 + 49 = c^2
      58 = c^2here we take the sqrt of both sides, eliminating ^2
      sqrt 58 = c
      7.6 = c <== the missing side is 7.6 cm.

(b) 25^2 + 15^2 = c^2
      625 + 225 = c^2
      850 = c^2
     sqrt 850 = c
     29.2 = c <== the missing side is 29.2 cm