Math Vocab Notes

What is the midsegment of a triangle?

A line segment that connects the midpoints of two sides of the triangle.

What is an Equidistant?

Something at equal distances from each other.

What’s a similar figure?

Geometric shapes that have the same shape but not necessarily the same size.

What is a similar polygon?

Figures that have the same shape but not necessarily the same size.

What's a base of a parallelogram?

Any one of the sides of a parallelogram.

What’s the Altitude of a parallelogram?

The perpendicular distance between one side (the base) and the line containing the opposite side.

What’s the height of a parallelogram?

The perpendicular distance between a chosen base and its opposite side.

What’s the base of a triangle?

Any side of a triangle that is perpendicular to its height or altitude.

What’s the height of a triangle?

A perpendicular line segment drawn from a vertex of the triangle to the line containing the opposite side.

What’s the height of a trapezoid?

The perpendicular distance between the two parallel sides, known as the bases.

What’s a Circle?

A round plane figure whose boundary consists of points equidistant from a fixed point.

What’s a center?

A point that is equidistant from all parts of the figure.

What’s a Diameter?

A straight line segment that passes through the center of the circle and has endpoints on the circle.

What’s a Radius?

A measure of distance from the center of a circular object to its outermost edge.

What are congruent circles?

Circles that have the same size and radius.

What are central angles?

An angle whose vertex is at the center of the circle, and whose sides are radii.

What is a semicircle?

Half of a circle.

What’s a Minor arc?

An arc of a circle that measures less than 180 degrees.

What’s a Major arc?

A portion of a circle's circumference that measures more than 180 degrees but less than 360 degrees.

What’s an Adjacent arc?

Two or more arcs that share a common endpoint and lie on the same circle.

What’s a circumference?

The perimeter of a circle, the distance around its boundary.

What is Pi?

The ratio of a circle's circumference to its diameter.

What’s Arc length?

The distance along a curved line, a segment of a circle's circumference.

What’s the sector of a circle?

A 'pie-shaped' region enclosed by two radii and the arc connecting their endpoints.

What’s the segment of a circle?

The area enclosed by an arc of a circle and a chord.

What’s a pyramid?

A three-dimensional geometric shape with a polygon as its base and lateral surfaces that are triangles meeting at a vertex.

What’s a Regular pyramid?

A pyramid whose base is a regular polygon.

What’s a cone?

A three-dimensional figure with a circular base and a curved surface that tapers to a point.

What’s a regular cone?

A cone whose axis is perpendicular to the base.

What is Volume?

A measure of the three-dimensional space that an object occupies.

What is a sphere?

A three-dimensional object where all points on its surface are equidistant from a central point.

What is the center of a sphere?

The fixed point that is equidistant from all points on the surface of the sphere.

What’s the radius of a sphere?

The distance from its center to any point on its surface.

What’s the diameter of the sphere?

A straight line that passes through the center of the sphere connecting two points on the surface.

What’s the Circumference of a sphere?

The length of its largest circle, also known as a great circle.

What’s the Great Circle?

The largest circle that can be drawn on any given sphere.

What is a Hemisphere?

Half of a sphere.