Geometry Midterm Vocabulary

Collinear

(of points) lying on or passing through the same straight line

Coplanar

In the same plane

Midpoint

The point on a line that is at an equal distance from either end (in the exact middle of the line)

Bisect

To divide equally into two equal parts

Vertex

A meeting point of two lines that form an angle

Acute Angle

An angle that measures less than 90°

Right Angle

An angle that measures 90°

Obtuse Angle

An angle that measures more than 90°

Complementary

When the measures of two angles add up to 90°

Supplementary

When the measures of two angles add up to 180°

Linear Pairs

Adjacent angles that add ip to 180°

Vertical Angles

Angles that are opposite each other when two lines cross. They share a vertex and are congruent

Converse

The hypothesis and conclusion are reversed.

If p → q, then q → p.

Inverse

When both the hypothesis and conclusion are negated

If p→q, then -p→-q

Contrapositive

Switch the hypothesis and conclusion of a conditional statement and negate both hypothesis and conclusion

If p→q, then -q→-p

Altitude

An altitude extends from a vertex of a triangle to and forms a right angle with the line that contains the opposite side

Median

A median extends from a vertex of a triangle to the midpoint of the opposite side

Angle Bisector

An angle bisector is a segment or ray that bisects a vertex angle

Perpendicular Bisector

A perpendicular bisector is a line or segment that forms a 90° with a side and is equidistant from both endpoints of the side (90° and go through midpoint of the line it goes through)

Pythagorean Theorem: Obtuse

c^2>a^2+b^2

Pythagorean Theorem: Acute

c^2

Pythagorean Theorem: Right

c^2=a^2+b^2

Volume of a Cylinder Equation

V=πr^2h

Surface Area of a Cylinder Equation

A=2πrh + 2πr^2