Help ASAP 15 points
A 20cm
B 15cm
C 12
D 17

Answer:
D
Step-by-step explanation:
square the 16 and 4.2 and sun them up due to the pythagorean theorem (a^2+b^2=c^2)
get 273.64 and take the sqrt of that to find c.
get 16.54 and round to 17 :)