What is the rule for triangle side lengths?

Triangle Inequality Theorem. The sum of the lengths of any two sides of a triangle is greater than the length of the third side.

Can the sides of a triangle have lengths 2 9 and 10?

No! It’s actually not possible! It turns out that there are some rules about the side lengths of triangles.

Can the sides of a triangle have lengths 2 8 and 12?

Therefore, the third side length must be greater than 4 and less than 8. Therefore, the third side length must be between 2 and 12. Because it is equal to the sum, not less than the sum, it is not possible that these could be the side lengths of a triangle.

Does a triangle with side lengths 15 12 9 exist?

Therefore yes, it is a right triangle.

Can these side lengths make a triangle?

SOLUTION: The sum of the lengths of any two sides of a triangle must be greater than the length of the third side. Since , you can not form a triangle with side lengths 9.9 cm, 1.1 cm, and 8.2 cm. ANSWER: No; The sum of the lengths of any two sides of a triangle must be greater than the length of the third side.

Can the sides of a triangle have lengths 2 12 and 13?

SOLUTION: Yes; The sum of the lengths of any two sides of a triangle must be greater than the length of the third side. ANSWER: Yes; Find the range for the measure of the third side of a triangle given the measures of two sides.

Can the sides of a triangle have lengths 2/10 and 12?

No; 10. SOLUTION: The sum of the lengths of any two sides of a triangle must be greater than the length of the third side.

What do you call a triangle with two equal sides?

A triangle with two sides of equal length is called an isosceles triangle. A triangle that has three sides of equal length is called an equilateral triangle. Figure 9.7. 12 shows both types of triangles.

How do you find the height of a triangle?

Figure 9.7. 11 – The height h of a triangle is the length of a line segment that connects the the base to the opposite vertex and makes a 90° angle with the base. For any triangle ΔABC, the sum of the measures of the angles is 180°. The perimeter of a triangle is the sum of the lengths of the sides.

What is the length of the side of an equilateral triangle?

The sides of an equilateral triangle are 9.4 cm, correct to the nearest one decimal place. Work out the upper bound of the side of this triangle. An isosceles triangle has two sides of length 7 km and 39 km.

How do you calculate the properties of a triangle?

From the known height and angle, the adjacent side, etc., can be calculated. They use knowledge, e.g., formulas (relations) Pythagorean theorem, Sine theorem, Cosine theorem, Heron’s formula, solving equations and systems of equations. The second stage is the calculation of the properties of the triangle from the known lengths of its three sides.