Special Right Triangles

What is a right triangle?

• A triangle that has one angle equal to 90°.

• A triangle with all sides of equal length.

• A triangle that has no angles equal to 90°.

• A triangle that has two angles equal to 45°.

What is an obtuse triangle?

• A triangle that has one angle greater than 90°.

• A triangle that has all angles less than 90°.

• A triangle that has exactly one right angle.

• A triangle that has two equal sides.

What is an acute triangle?

• A triangle where all three angles are less than 90°.

• A triangle with one angle greater than 90°.

• A triangle with all angles equal to 90°.

• A triangle with two angles less than 90° and one angle equal to 90°.

What is an equilateral triangle?

• A triangle where all three sides are equal in length and all angles are 60°.

• A triangle with one angle greater than 90°.

• A triangle that has two sides of equal length.

• A triangle where all angles are 90°.

Can a triangle have side lengths of 4, 6, and 15?

• Yes, because the side lengths satisfy the Triangle Inequality Theorem.

• No, because 4 + 6 is not greater than 15, violating the Triangle Inequality Theorem.

• Yes, because any three lengths can form a triangle.

• No, because the longest side must be less than the sum of the other two sides.

What type of triangle is formed by angles of 60°, 60°, and 60°?

• An isosceles triangle.

• An equilateral triangle.

• A scalene triangle.

• A right triangle.

What is the formula for the area of a triangle?

• Area = base * height

• Area = 1/2 * base * height

• Area = base + height

• Area = base - height

What is the Triangle Inequality Theorem?

• The sum of the lengths of any two sides of a triangle must be greater than the length of the third side.

• The sum of the lengths of all three sides of a triangle must equal 180 degrees.

• The length of one side of a triangle must be equal to the sum of the other two sides.

• The area of a triangle is equal to half the product of its base and height.

What is an isosceles triangle?

• A triangle that has all sides of equal length.

• A triangle that has at least two sides of equal length and the angles opposite those sides are equal.

• A triangle that has no sides of equal length.

• A triangle that has one angle greater than 90 degrees.

What is the classification of a triangle with side lengths 10, 18, and 40?

• A triangle

• An obtuse triangle

• Not a triangle, because 10 + 18 is not greater than 40.

• An acute triangle