Angles & Lines
This type of angle is less than 90 degrees.
What is an acute angle?
A triangle with all sides and angles equal.
What is an equilateral triangle?
This is the distance from the center to the edge of a circle.
What is the radius?
The formula to find distance between two points.
What is the distance formula: √[(x₂ - x₁)² + (y₂ - y₁)²]?
a transformation that slides a figure without turning it.
What is a translation?
These angles are formed when two lines intersect and are opposite each other
What are vertical angles?
This rule states that the sum of a triangle’s interior angles is always this.
What is 180 degrees?
A line that touches a circle at exactly one point.
What is a tangent?
The midpoint between (2, 4) and (6, 8).
What is (4, 6)?
A figure that maintains congruency after rotation, reflection, or translation.
What is a rigid transformation?
When two parallel lines are cut by a transversal, these angles are equal.
What are corresponding angles?
The Pythagorean Theorem applies only to this kind of triangle.
What is a right triangle?
A segment with endpoints on the circle that passes through the center.
What is a diameter?
The slope of a line perpendicular to a line with slope 2.
What is -1/2?
A transformation that changes the size of a figure.
What is a dilation?
This postulate proves lines are parallel if same-side interior angles are supplementary.
What is the Converse of the Same-Side Interior Angles Postulate?
This theorem proves triangle similarity using side ratios.
What is the Side-Side-Side (SSS) Similarity Theorem?
The measure of a central angle is equal to this.
What is the measure of its intercepted arc?
The equation of a circle with center (0,0) and radius 5.
What is x² + y² = 25?
The image of point (2, 5) after a reflection over the y-axis.
What is (-2, 5)?
These two angle pairs are congruent and alternate sides of a transversal.
What are alternate interior and alternate exterior angles?
This center of a triangle is the intersection of the perpendicular bisectors.
What is the circumcenter?
The formula for the area of a sector is this.
What is (θ/360) × πr²?
The coordinates of the reflection of (3, -2) over the x-axis.
What is (3, 2)?
A rotation of 90° counterclockwise about the origin changes (x, y) to this.
What is (-y, x)?