2. Angles Acute Angle Obtuse Angle Right Angle Straight Angle An acute angle is an angle that is less than 90 ° An obtuse angle is an angle that is more than 90 ° A right angle is an angle that is exactly 90 ° A straight angle is an angle that is always 180 °
3. Complementary angle supplementary and complementary angles Supplementary angles Complementary angles are two angles added up to 90 ° Supplementary angles are two angles added up to 180 ° 75 ° 15 ° 118 ° 62 °
4. LINES IN A PLANE Parallel Lines Intersecting lines Perpendicular lines Two lines in the same plane that do not intersect. Two lines that meet at a point. Two lines that intersect to form a right angle.
5. Classifying traingles by angle measures Acute triangle An acute angle is an angle that has three acute sides Right triangle Obtuse triangle An acute angle is an angle that has one right angle An obtuse angle has one obtuse angle 60 ° 50 ° 70 ° 50 ° 25° 120° 35° 40°
6. Triangles classifyed by length Equilateral Triangles Isosceles Triangles Scalene Triangles Equilateral triangles has 3 congruent sides Scalene triangles has no congruent sides Isosceles triangles has at least 2 congruent sides 90 in 90 in 8m 90 in 5m 8m 14ft 5ft 11ft
7. Quadrilaterals Names Diagram Definition Real World Pics Trapezoid Parallelogram Rectangle Rhombus Square A square is a parallelogram with 4 right angles and 4 congruent sides. A rhombus is a Parallelogram with 4 congruent sides. A rectangle is a parallelogram with four right angles. A parallelogram is a quadrilateral with 2 pairs of sides. A trapezoid is a quadrilateral with exactly one pair of sides. A geometric figure that is made up of four line segments called sides.
8. polygon Geometric figure that is made up of three or more line segments. Triangle Quadrilateral Pentagon Hexagon Octagon A polygon with eight sides. A polygon with six sides and vertices. A polygon with four sides or edges and four vertices or corners. A polygon with three corners or vertices and three sides or edges which are line segments. A polygon with five sides.
9. SPECIAL ANGLES Adjacent angles- two angles that share a common side and vertex. Vertical angles- a pair of opposite angles that formed when two lines meet at a point. 1 1 2 3 4 Examples: 1&2,2&3,4&1,4&3 Examples 1&3 2&4 Congruent angles- the angles that have the exact same measure 1 2 4 1 2 4 Examples 1&3 2&4 3 3
10. Corresponding Angles When a line intersects two parallel lines. 1 4 8 2 5 3 7 6 Examples 1&5, 2&6, 3&7, 4&8