Triangle Sum & Triangle Inequality

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

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

If one angle of a triangle is 90 degrees, what type of triangle is it?

Back

It is a right triangle.

Front

What is the relationship between the sides and angles of a triangle?

Back

The longest side of a triangle is opposite the largest angle, and the shortest side is opposite the smallest angle.

Front

Can the sides 8, 10, and 20 form a triangle?

Back

No, because 8 + 10 is not greater than 20.

Front

Can the sides 11, 7, and 21 form a triangle?

Back

No, because 11 + 7 is not greater than 21.

Front

What is the measure of the third angle if two angles of a triangle are 45 degrees and 60 degrees?

Back

The third angle is 75 degrees, since 180 - (45 + 60) = 75.

Front

If a triangle has angles measuring 30 degrees and 60 degrees, what is the measure of the third angle?

Back

The third angle measures 90 degrees.

Front

What is the minimum length of a side of a triangle if the other two sides are 5 and 7?

Back

The minimum length must be greater than 2 (7 - 5).

Front

What is the maximum length of a side of a triangle if the other two sides are 5 and 7?

Back

The maximum length can be less than 12 (5 + 7).