Triangle inequality

Front

What is the Triangle Inequality Theorem?

Back

The Triangle Inequality Theorem states that for any triangle, the sum of the lengths of any two sides must be greater than the length of the third side.

Front

Can a triangle have sides of lengths 3, 4, and 9?

Back

No, because 3 + 4 is not greater than 9.

Front

What type of triangle has all sides of different lengths?

Back

Scalene triangle.

Front

What type of triangle has at least two sides of equal length?

Back

Isosceles triangle.

Front

What type of triangle has all angles less than 90 degrees?

Back

Acute triangle.

Front

What type of triangle has one angle greater than 90 degrees?

Back

Obtuse triangle.

Front

What type of triangle has one angle equal to 90 degrees?

Back

Right triangle.

Front

Determine the type of triangle with sides 20, 21, and 25.

Back

Acute triangle.

Front

Does a triangle with sides 15, 12, and 9 exist?

Back

Yes, it satisfies the triangle inequality.

Front

Determine the type of triangle with sides 10, 18, and 40.

Back

Not a triangle.