Lines & Angles
Two lines that intersect to form a perfect 90-degree angle.
What are perpendicular lines?
A triangle with three sides of completely different lengths.
What is a scalene triangle?
A straight line segment that passes through the center of a circle and connects two points on the edge.
What is the diameter?
The famous theorem stating a2 + b2 = c2 for right triangles.
What is the Pythagorean Theorem?
The point (0,0) on a coordinate plane where the x-axis and y-axis intersect.
What is the origin?
An angle that measures greater than 90 degrees but less than 180 degrees.
What is an obtuse angle?
The sum of the interior angles of any standard triangle.
What is 180 degrees?
The mathematical term for the perimeter of a circle.
What is the circumference?
In a right triangle, this is the name given to the longest side, opposite the right angle.
What is the hypotenuse?
In the coordinate equation y=mx+b , the letter m represents this property of the line.
What is the slope?
This term describes two angles whose measurements add up to exactly 90 degrees.
What are complementary angles?
A regular polygon with exactly eight sides.
What is an octagon?
A line segment whose endpoints both lie on a circle, but does not necessarily pass through the center.
What is a chord?
This ancient Greek mathematician is known as the "Father of Geometry" and wrote the book Elements.
Who was Euclid?
This formula uses the square root of (x2-x1)2+(y2-y1)2 to find the space between two points.
What is the distance formula?
When two parallel lines are cut by a transversal, these interior angles on opposite sides of the transversal are equal.
What are alternate interior angles?
This formula,(n-2)x180, calculates the total sum of these angles in a polygon.
What are interior angles?
This 3D shape is formed by rotating a right triangle around one of its legs.
What is a cone?
This theorem states that if a triangle is inscribed inside a circle where one side is the diameter, the opposite angle is a right angle.
What is Thales's Theorem?
The geometric transformation that flips a figure over a line, creating a mirror image.
What is a reflection?
A straight line that touches a curve or circle at exactly one point without intersecting it.
What is a tangent line?
A quadrilateral with exactly one pair of parallel sides.
What is a trapezoid?
The region of a circle bounded by two radii and an arc, often looking like a slice of pie.
What is a sector?
For any convex polyhedron, this formula states that Vertices minus Edges plus Faces equals two (v-e+f=2)
What is Euler's Formula?
Two non-vertical lines are perpendicular if the product of their slopes equals this specific number.
What is -1?