Question

question 7 of 10
classify the following triangle. check all that apply.
a. equilateral
b. right
c. isosceles
d. acute
e. scalene
f. obtuse

Explanation:

• Equilateral: An equilateral triangle has all sides equal and all angles equal to \(60^{\circ}\). Here, sides are \(10\), \(11\), \(12.1\) and angles are \(51^{\circ}\), \(59^{\circ}\), \(70^{\circ}\), so not equilateral.
• Right: A right - triangle has one \(90^{\circ}\) angle. No \(90^{\circ}\) angle here.
• Isosceles: An isosceles triangle has at least two equal sides. Sides are \(10\), \(11\), \(12.1\) (no two equal), so not isosceles.
• Acute: An acute triangle has all angles less than \(90^{\circ}\). \(51^{\circ}<90^{\circ}\), \(59^{\circ}<90^{\circ}\), \(70^{\circ}<90^{\circ}\), so it is acute.
• Scalene: A scalene triangle has all sides of different lengths. Sides \(10\), \(11\), \(12.1\) are all different, so it is scalene.
• Obtuse: An obtuse triangle has one angle greater than \(90^{\circ}\). No such angle here.

Answer:

D. Acute, E. Scalene