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Answer:</h3>
A) Isosceles
E) Obtuse
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Step-by-step explanation:</h3>
Ways to Define a Triangle
Triangles can be defined in two ways: by angles and by sides. Equilateral, isosceles, and scalene are based on side length. Acute, right, and obtuse are based on angle measurements. Triangle may only fall under one category for side length and one for angle measure (2 categories total).
Side Length
First, let's define equilateral, isosceles, and scalene.
- Equilateral - All 3 sides of the triangle are congruent (equilateral are always acute angles).
- Isosceles - 2 of the sides are congruent.
- Scalene - There are no congruent sides; each side has a different length.
The triangle above has 2 congruent sides as shown by the tick marks on the left and right sides. This means the triangle is isosceles.
Angle Measurements
Now, let's define acute, right, and obtuse.
- Acute - All 3 angles are less than 90 degrees; all angles are acute.
- Right - 1 of the angles is exactly 90 degrees; it has a right angle.
- Obtuse - 1 of the angles is greater than 90 degrees; there is an obtuse angle.
The largest angle in the triangle is 98 degrees, which is obtuse. This means that the triangle is obtuse.
