Page 261 - ICSE Math 6

ANGLES

Congruent Angles
0° More than 0°
Angles of the same magnitude Less than 90°

Linear Pair Zero Acute
Two adjacent supplementary angles
360° Complete Types of Right 90°
Complementary Angles Angles
Two angles with the sum of their measures as 90° Reflex Obtuse
Less than 180°

Supplementary Angles Less than 360° Straight More than 90°
Two angles with the sum of their measures as 180°
More than 180°
180°
Vertically Opposite Angles
Angles formed by two intersecting lines without any common arm

Adjacent Angles
Two angles lying on the opposite sides of a common arm and having the same vertex

TRIANGLES AND QUADRILATERALS

Polygon
A simple closed figure made up of line segments only
Vertex EXTERIOR

A A A
polygon polygon polygon Angle
with 3 sides. with 5 with 7
Triangle sides. sides. Side Side
Pentagon Heptagon INTERIOR

A polygon A A
with 4 polygon polygon Vertex Angle Angle Vertex
sides. with 6 with 8 Side
sides.
Quadrilateral sides. Octagon
Hexagon

Median of a Triangle Altitude of a Triangle
Joins the vertex of a triangle to the It is the perpendicular drawn from the
midpoint of the opposite side. vertex to the opposite side of a triangle.
Always lies inside the triangle. May also lie outside the triangle.

Point of intersection of medians is Point of intersection of the altitudes is
known as centroid. known as orthocentre.

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