Answer:
c ≈ 14.76
Explanation:
In right triangle ABC, you have short sides a=7 and b=13. You want the length of the hypotenuse, 'c'.
Pythagorean theorem
The Pythagorean theorem tells you the relationship between the sides of a right triangle is ...
c² = a² +b²
Application
Filling in the given values, we have ...
c² = 7² +13² = 49 +169 = 218
c = √218 ≈ 14.7648
Rounding to hundredths, we have ...
c ≈ 14.76
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Additional comment
Your posted question asks for the value of C (capitalized). That refers to the right angle, so its value is C = 90°. It is always helpful if you ask for what you really want to know.