Answer:
80.13
Step-by-step explanation:
Since a rectangle being cut by a diagonal forms a right triangle, the Pythagorean theorem is applicable. The Pythagorean theorem states;
[tex]a^{2} + b^{2} = c^{2}[/tex]
Where "a" and "b" are the legs, or sides of the triangle, and "c" is the hypotenuse or diagonal.
The sides or legs are, 70 and 39, all one simply has to do now is substitute them into the formula and solve for "c".
[tex]70^{2} + 39^{2} = c^{2}\\4900 + 1521 = c^2\\6421 = c^2\\c = \sqrt{6421}\\[/tex]
c ~ 80.13
