Which type of triangle has side measures of 5 cm, 9 cm, and 12.7 cm and one angle measure of 128°? (1 point) Responses acute isosceles acute isosceles obtuse scalene obtuse scalene obtuse isosceles obtuse isosceles acute scalene acute scalene

Answer 1

To classify the triangle with sides measuring 5 cm, 9 cm, and 12.7 cm, and one angle measuring 128°, we can use the definitions of triangle types:

1. Type based on sides:
   • Scalene Triangle: A triangle with all sides of different lengths.
   • Isosceles Triangle: A triangle with at least two equal sides.

Since all three side lengths (5 cm, 9 cm, and 12.7 cm) are different, this triangle is scalene.

2. Type based on angles:
   • Acute Triangle: All angles are less than 90°.
   • Right Triangle: One angle is exactly 90°.
   • Obtuse Triangle: One angle is greater than 90°.

With one angle measuring 128°, which is greater than 90°, the triangle is classified as obtuse.

Putting both classifications together, the triangle is an obtuse scalene triangle.

So, the correct response is: obtuse scalene.