Constructing triangles, triangle inequality and sum theorem

Front

What is the sum of the angles in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees.

Front

If two angles of a triangle are 30 and 70 degrees, what is the measure of the third angle?

Back

80 degrees.

Front

What is the Triangle Inequality Theorem?

Back

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

Front

Which set of side lengths can form a triangle? 6, 8, 13 or 7, 9, 18?

Back

6, 8, 13 can form a triangle.

Front

Can a triangle have two right angles?

Back

No, a triangle cannot have two right angles.

Front

Can a triangle have three acute angles?

Back

Yes, a triangle can have three acute angles.

Front

What is an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

What is an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90 degrees but less than 180 degrees.

Front

What is a right angle?

Back

A right angle is an angle that measures exactly 90 degrees.

Front

How many lines of symmetry does an equilateral triangle have?

Back

An equilateral triangle has 3 lines of symmetry.