Geometry-AS-PSAT

Collinear

Points that could be connected by a straight line.

Intersecting lines

Two lines that meet at one point.

Concurrent lines

More than two line lines intersecting at a single point.

Perpendicular lines

Two lines that meet at one point and form a 90 degree angle.

Transversal

A line that intersects two lines.

Bisector

A line that intersects something else and divides it into two equal parts.

Perpendicular bisector

A bisector which forms a 90 degree angle.

Complementary angles

Two angles that equal 90 degrees when combined.

Supplementary angles

Angles that equal 180 degrees when combined.

Adjacent angles

Angles that share a vertex and a side.

Polygon

A closed, two-dimensional figure, with three or more straight sides.

Regular polygon

Polygons with congruent sides and angles.

Formula for sum of interior angles

(n-2)180. The sides is n.

Heron’s formula

A=Sqrt[s(s-a)(s-b(s-c)]. This is used for triangles.

Altitude

A line in the middle of a triangle perpendicular to a side, from a vertex. It could be used as height when find the area of a triangle.

Median (of triangle)

A line segment that goes from a vertex to the middle point of the opposite side.

Orthocenter

The point where the altitude meet.

Centroid

The point where the medians meet.

Inscribed

A shape is inside another shape and the inner shape is touching the outer shape.

Circumscribed

The exact opposite of inscribed.

Volume of sphere

V=4/3(pi)(r³).

Surface area for sphere

SA=4(pi)(r²).

Volume of a Pyramid and Cone

V=1/3Bh.

Volume of any prism

V=Bh.

Surface area of any prism

SA=2B+ph