Answer: Yes, that is a right triangle.
Step-by-step explanation:
To tell whether this is a right triangle or not you use a^2 + b^2= c^2
c is the hypotenuse the hypotenuse is the longest side of a right triangle, opposite the right angle. A and B can be either of the triangles sides.
To get this answer: 80^2+39^2 = 89^2
6400 + 1521 = 7921
7921=7921
Since they are the same this IS a right triangle. Here is a little help for if the a question asks if you have a right acute or obtuse. To tell if you have an acute triangle the sign will be a greater than sign for ex) 180 > 169. If you have a obtuse triangle the sign would be a less than sign for ex) 120 < 200.
Here is a problem like that if you do not understand:
6^2 +12^2 = 13^2 ( remember c is the hypotenuse)
36+144= 169
180 > 169
Have a nice day!
