Question

which triangle is a scalene triangle?

a
8 cm, 8 cm

b
9 cm

c
10 cm, 12 cm, 9 cm

d
8 cm, 8 cm, 8 cm

Explanation:

Define a scalene triangle

A scalene triangle is a triangle in which all three sides have different lengths.

Analyze the given options

• Option A: Two sides are labeled \(8\text{ cm}\). This is an isosceles triangle.
• Option C: The sides are \(10\text{ cm}\), \(12\text{ cm}\), and \(9\text{ cm}\). All three sides have different lengths.
• Option D: All three sides are labeled \(8\text{ cm}\). This is an equilateral triangle.

Identify the correct option

Option C has three unequal side lengths (\(10\text{ cm}
eq 12\text{ cm}
eq 9\text{ cm}\)), making it a scalene triangle.

Answer:

• (A) An isosceles triangle with side lengths of \(8\text{ cm}\), \(8\text{ cm}\), and an unlabeled base.
• (C) A triangle with side lengths of \(10\text{ cm}\), \(12\text{ cm}\), and \(9\text{ cm}\). (Correct answer)
• (D) An equilateral triangle with side lengths of \(8\text{ cm}\), \(8\text{ cm}\), and \(8\text{ cm}\).