Geometry - Triangles

Question 1

What is a traingle?

Answer 1

A closed figure consisting of three line segments linked end-to-end.
A 3-sided polygon.

Question 2

In a traingle, the shortest side is always opposite the smallest interior angle.

True or False?

Answer 2

True

Question 3

In a traingle, the longest side is always opposite the largest interior angle

True or False?

Answer 3

True

Question 4

The interior angles of a triangle always add up to 180°

True or False?

Answer 4

True

Question 5

The exterior angles of a triangle always add up to 360°

True or False?

Answer 5

True

Question 6

What is an Isosceles Triangle?

Answer 6

A triangle which has two of its sides equal in length.

Properties

• The unequal side of an isosceles triangle is usually referred to as the ‘base’ of the triangle.
• The base angles of an isosceles triangle are always equal.
• When the 3rd angle is a right angle, it is called a “right isosceles triangle”.
• The altitude is a perpendicular distance from the base to the topmost vertex.

Question 7

What is a Equilateral Triangle?

Answer 7

A triangle which has all three of its sides equal in length.

Properties

• All three angles of an equilateral triangle are always 60°.
• With an equilateral triangle, the radius of the incircle is exactly half the radius of the circumcircle.

Question 8

What is a Scalene Triangle?

Answer 8

A triangle where all three sides are different in length.

Question 9

What is a right angle traingle?

Answer 9

A triangle where one of its interior angles is a right angle (90 degrees).

Properties

• A right triangle can also be isosceles if the two sides that include the right angle are equal in length
• A right triangle can never be equilateral, since the hypotenuse (the side opposite the right angle) is always longer than either of the other two sides.

Question 10

What is Obtuse Triangle?

Answer 10

A triangle where one of the internal angles is obtuse (greater than 90 degrees).

Question 11

What is an acute traingle?

Answer 11

A triangle where all three internal angles are acute (less than 90 degrees).

Question 12

In a traingle, An exterior angle of a triangle is equal to the sum of the opposite interior angles.

True or False?

Answer 12

True

Question 13

An exterior angle of a triangle is always larger then either opposite interior angle.

True or False?

Answer 13

True

Question 14

Any side of a triangle is always shorter than the sum of the other two sides.

True or False

Answer 14

True

The triangle inequality theorem states that any side of a triangle is always shorter than the sum of the other two sides.

Question 15

A triangle cannot be constructed from three line segments if any of them is longer than the sum of the other two.

True of False?

Answer 15

True

Triangle Inequality Theorem Converse

A triangle cannot be constructed from three line segments if any of them is longer than the sum of the other two.

Question 16

What is the perimeter of a traingle?

Answer 16

The total distance around the outside of a triangle