5. given the following triangle side lengths, identify the triangle as acute, right or obtuse. show your work. a. 3in, 4in, 5 in b. 5in, 6in, 7in c. 8in, 9in, 12in

A.3in, 4in, 5 in
5^2 ?  3^2 + 4^
25   ?  9 + 16
25   =  25
Because the two sides are equal, this is a right triangle.

b.5in, 6in, 7in
7^2  ?  5^2 + 6^2
49   ?  25 + 36
49   <  61

Because 49 < 61, this is an acute triangle.

c.8in, 9in, 12in
12^2  ?  8^2 + 9^2
144    ? 64 + 81
144    < 145

Because 144< 145 , this is an acute triangle.