Essential Geometry Vocabulary: Circles and Triangles

The video tutorial from Moomoomath covers essential vocabulary and concepts related to circles and triangles. It begins with an introduction to circle vocabulary, including terms like center, radius, diameter, and circumference. The tutorial then moves on to triangle vocabulary, discussing the triangle inequality theorem, medians, orthocenter, and altitudes. It also covers the classification of triangles by side lengths and angles, such as scalene, isosceles, equilateral, acute, right, obtuse, and equiangular triangles. Finally, the video explains different types of angles, including acute, right, obtuse, and straight angles, and how to measure them using a protractor.

What is the term for the distance from the center of a circle to any point on the circle?

• Circumference

• Tangent

• Radius

• Diameter

Which line intersects a circle at exactly one point?

• Diameter

• Secant

• Tangent

• Radius

According to the triangle inequality theorem, the sum of the lengths of any two sides of a triangle is:

• Not related to the length of the third side

• Greater than the length of the third side

• Less than the length of the third side

• Equal to the length of the third side

What is the point called where the three altitudes of a triangle intersect?

• Incenter

• Centroid

• Orthocenter

• Circumcenter

In a right triangle, the length of the altitude is the geometric mean of the lengths of which segments?

• The two segments of the hypotenuse

• The altitude and one leg

• The two legs

• The hypotenuse and one leg

Which type of triangle has no congruent sides?

• Right

• Equilateral

• Isosceles

• Scalene

What is the measure of a straight angle?

• 360 degrees

• 270 degrees

• 180 degrees

• 90 degrees

Which angle is less than 90 degrees?

• Obtuse angle

• Acute angle

• Straight angle

• Right angle

What is the reference angle used to classify other angles?

• Right angle

• Obtuse angle

• Acute angle

• Straight angle

When measuring an angle with a protractor, where should you place the vertex?

• At the edge of the protractor

• At the center of the protractor

• At the 180-degree mark

• At the 90-degree mark