Please help and show all work

1) a^2 = c^2 - b^2
a^2 = 5^2 - 4^2
a^ 2 = 9
(Square root 9)
a = 3

2) a^ 2 + b^2 = c^2
8^2 + 4^2 = c^2
80 = c^2
(Square root of 80)
C = 8.9 cm

3) a^2 + b^2 = c^2
6^2 + 2^2 = c^2
40 = c^2
(Square root of 40)
C = 6.3 cm

4) a^2 + b^2 = c^2
10^2 + 24^2 = c^2
676 = c^2
(Square root of 676)
C = 26

5) a^2 + b^2 = c^2
6^2 + 5^2 = c^2
61 = c^2
C = 7.8cm

6) a^2 + b^2 = c^2
12^2 + 12^2 = c^2
288 = c^2
C = 16.97cm

7) 8^2 + 6^2 = c^2
100 = c^2
C = 10

8) a^2 = c^2 - b^2
a^2 = 25^2 - 20^2
a^2 = 225
a = 15

9) a^2 = 14^2 - 9^2
a^2 = 115
a = 10.7cm

10) a^2 = 20^2 - 15^2
a^2 = 175
a = 13.2cm

11) Does 15^2 + 8^2 = 17^2?
289 = 289

Yes it’s a right angled triangle because 15^2 + 8^2 = 17^2

Do the same for the others

12) 7^2 + 5^2 = 74
9^2 = 81

So it’s not a right angled triangle

13) 5^2 + 12^2 = 169
13^2 = 169

It is a right angled triangle

14) 9^2 + 12^2 = 225
16^2 = 256

Not a right angled triangle

15) 10^2 + 24^2 = 676
26^2 = 676

It is a right angled triangle

16) 2^2 + 2^2 = 8
3^2 = 9

Not a right angled triangle

Im just here to correct what the other person wrote so I dont have to write everything I read it and its right please give her a thanks

Ai just took the test

Four thousand nineteen hundred thousandths in standard form is 4900