A triangle whose two sides are equal is known as

Options

A. acute triangle
B. an isosceles triangle
C. a scalene triangle
D. a right triangle

Answer

To solve the question "A triangle whose two sides are equal is known as," we will analyze the options provided and determine the correct answer step by step.

### Step-by-Step Solution:

1. **Understanding Triangle Types:**
- We need to identify the characteristics of different types of triangles based on their sides and angles.

2. **Option Analysis:**
- **Option A: Acute Triangle**
- An acute triangle has all angles less than 90 degrees. This does not relate to the sides being equal.
- **Option B: Isosceles Triangle**
- An isosceles triangle is defined as a triangle with at least two sides that are equal in length. This matches our question.
- **Option C: Skeleton Triangle**
- A skeleton triangle is not a standard term in geometry. It is likely a misinterpretation or incorrect term. Typically, it refers to a triangle where no sides are equal, which does not fit our question.
- **Option D: Right Triangle**
- A right triangle has one angle that is exactly 90 degrees. This does not specify anything about the sides being equal.

3. **Conclusion:**
- After analyzing all the options, the only correct answer that fits the description of a triangle with two equal sides is **Option B: Isosceles Triangle**.

### Final Answer:
A triangle whose two sides are equal is known as an **Isosceles Triangle**.

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