Scalene Triangle Practice Problems and Exercises

Master scalene triangles with step-by-step practice problems. Learn to identify and solve scalene triangle exercises with detailed solutions and examples.

📚What You'll Practice with Scalene Triangles
  • Identify scalene triangles by examining side lengths and properties
  • Distinguish scalene triangles from isosceles and equilateral triangles
  • Calculate perimeter and area of scalene triangles using given measurements
  • Solve real-world problems involving scalene triangle applications
  • Apply triangle inequality theorem to verify scalene triangle existence
  • Classify triangles based on side lengths and angle measures

Understanding Scalene triangle

Complete explanation with examples

Definition of Scalene Triangle

An scalene triangle is a triangle that has all its sides of different lengths.

Detailed explanation

Practice Scalene triangle

Test your knowledge with 20 quizzes

Given the size of the 3 sides of the triangle, is it an equilateral triangle?

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Examples with solutions for Scalene triangle

Step-by-step solutions included
Exercise #1

Calculate the size of angle X given that the triangle is equilateral.

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Step-by-Step Solution

Remember that the sum of angles in a triangle is equal to 180.

In an equilateral triangle, all sides and all angles are equal to each other.

Therefore, we will calculate as follows:

x+x+x=180 x+x+x=180

3x=180 3x=180

We divide both sides by 3:

x=60 x=60

Answer:

60

Video Solution
Exercise #2

Can a right triangle be equilateral?

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the properties of a right triangle.
  • Step 2: Identify the properties of an equilateral triangle.
  • Step 3: Compare these properties to determine if a right triangle can be equilateral.

Now, let's work through each step:

Step 1: A right triangle is defined by having one angle equal to 9090^\circ.
Step 2: An equilateral triangle is defined by having all three sides of equal length and all three angles equal to 6060^\circ.
Step 3: Compare the angle measurements: A right triangle cannot have all angles 6060^\circ because it requires one angle to be 9090^\circ. Likewise, an equilateral triangle cannot have a 9090^\circ angle, as all its angles must be 6060^\circ.

Therefore, it is impossible for a right triangle to be equilateral, as they fundamentally differ in angle requirements.

The answer to the problem is No.

Answer:

No

Video Solution
Exercise #3

Choose the appropriate triangle according to the following:

Angle B equals 90 degrees.

Step-by-Step Solution

Let's note in which of the triangles angle B forms a right angle, meaning an angle of 90 degrees.

In answers C+D, we can see that angle B is smaller than 90 degrees.

In answer A, it is equal to 90 degrees.

Answer:

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Video Solution
Exercise #4

Does every right triangle have an angle _____ The other two angles are _______

Step-by-Step Solution

Let's analyze the problem to understand how the angles are defined in a right triangle.

A right triangle is defined as a triangle that has one angle equal to 9090^\circ. This is known as a right angle. Because the sum of all angles in any triangle must be 180180^\circ, the two remaining angles must add up to 9090^\circ (i.e., 18090180^\circ - 90^\circ).

In a right triangle, the right angle is always present, leaving the other two angles to be less than 9090^\circ each. These angles are called acute angles. An acute angle is an angle that is less than 9090^\circ.

To summarize, the angle types in a right triangle are:

  • One angle that is 9090^\circ (a right angle).
  • Two angles that are each less than 9090^\circ (acute angles).

Given the choices, the description "Straight, sharp" correlates to the angle types in a right triangle, as "Straight" can be associated with the 9090^\circ angle (though it's generally called a right angle) and "Sharp" correlates with acute angles.

Therefore, the correct aspect of the other two angles in a right triangle are straight (right) and sharp (acute), which matches the correct choice.

Therefore, the solution to the problem is Straight, sharp.

Answer:

Straight, sharp

Video Solution
Exercise #5

Does the diagram show an obtuse triangle?

Step-by-Step Solution

To determine if the triangle in the diagram is obtuse, we will visually assess the angles:

  • Step 1: Identify the angles in the diagram. The triangle has three angles, with one angle appearing between the horizontal base and the left slanted side.
  • Step 2: Evaluate the angle between the base and the left side. If it opens wider than a right angle, it's considered obtuse. This angle seems to be greater than 9090^\circ, indicating obtuseness.
  • Step 3: Conclude based on visual inspection. Since this key angle is greater than 9090^\circ, the triangle must be an obtuse triangle.

Therefore, the solution to the problem is Yes; the diagram does show an obtuse triangle.

Answer:

Yes

Video Solution

Frequently Asked Questions

What is a scalene triangle and how do I identify one?

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A scalene triangle is a triangle where all three sides have different lengths. To identify one, measure or compare all three sides - if no two sides are equal, it's a scalene triangle.

What's the difference between scalene, isosceles, and equilateral triangles?

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• Scalene triangle: All three sides have different lengths • Isosceles triangle: Two sides have equal lengths • Equilateral triangle: All three sides have equal lengths

How do you find the perimeter of a scalene triangle?

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To find the perimeter of a scalene triangle, add all three side lengths together. Since all sides are different, you simply calculate: Perimeter = side a + side b + side c.

Can a scalene triangle be a right triangle?

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Yes, a scalene triangle can be a right triangle. A triangle can be classified by both its sides (scalene, isosceles, equilateral) and its angles (acute, right, obtuse) independently.

What are some real-world examples of scalene triangles?

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Real-world scalene triangles include: 1. Roof trusses in construction 2. Triangular road signs with unequal sides 3. Mountain peaks viewed from the side 4. Sail shapes on boats

How do you prove three sides can form a scalene triangle?

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Use the triangle inequality theorem: the sum of any two sides must be greater than the third side. Check all three combinations: a+b>c, a+c>b, and b+c>a.

What formulas work for calculating scalene triangle area?

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For scalene triangles, you can use: • Heron's formula: √[s(s-a)(s-b)(s-c)] where s = (a+b+c)/2 • Base × height ÷ 2 (if height is known) • ½ab sin(C) using two sides and included angle

Are scalene triangles harder to work with than other triangles?

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Scalene triangles require more careful calculation since no sides or angles are equal, but they follow the same geometric principles. With practice, solving scalene triangle problems becomes straightforward.

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