1.
a^2+b^2=c^2
easy
a=a
b=13
c=21
a^2+13^2=21^2
a^2+169=441
minus 169 both sides
a^2=272
sqrt both sides
a=16.4924
D is answer
2. same thing
a=18
b=26
18^2+26^2=c^2
324+676=c^2
1000=c^2
sqrt both sides
31.6228=c
C is answer
3.
one way is to plug them in
remember that hypotonuse is longest side
A. 7^2+24^2=25^2, is that true?, yes it is treu
answer is A
4.
legs are 6 and 4
a=6
b=4
c=x
4^2+6^2=x^2
16+36=x^2
52=x^2
sqrt both sides
7.2111=x
7.2=x
5.c=20
a=x
b=14
x^2+14^2=20^2
x^2+196=400
minus 196 both sides
x^2=204
sqrt both sides
x=14.2829
x=14.3
1. D
2. C
3. A
4. 7.2
5. 14.3