the answer for this question is B.20
Answer:
Step-by-step explanation: 5
11in
Step-by-step explanation:
a^2+b^2=c^2 when c is the hypotenuse
10^2+sqrt21^2=c^2
100+21=c^2
121=c^2
11=c
Answer: <em>it will actually be -3, 7</em>