А 1 cm
B. 5 cm
C. 11 cm
D. 25 cm

5 is the answer

here we have hypoteaus and base

so by using pythagoreaus theorem

p^2 = h^2 - b^2

p^2 = 13^2 - 12^2

p^2 = 169 - 144

p^2 = 25

p = root under 25

p = 5

5 cm

Step-by-step explanation:

A^2+B^2=C^2

12^2+B^2=13^2

144+B^2=169 (You have to subtract 144 from both sides to get B^2 by its self)

-144       = -144

B^2= 25 (To get rid of the square you have to find the square root)

Square root of 25 = 5cm