Page 166 - Math Skill - 5

164 Maths

MIND MAP

Types of Angles Geometry Types of Lines

P

q
O Q COPLANER LINES
If q = 0° (Zero angle) Triangles

If q = 90° (Right angle) A B Plain
If q = 180° (Straight angle) On the basis of sides On the basis of angles C D
If q = 360° (Complete angle)
If 90° < q < 180° (Obtuse angle) INTERSECTING LINES
SCALENE
If 0° < q < 90° (Acute angle) No sides equal ACUTE ANGLED
If 180° < q < 360° (Reflex angle) All angles are acute A Q

B
ISOSCELES OBTUSE ANGLED P
Two sides equal One angle is obtuse
PERPENDICULAR LINES

C
EQUILATERAL RIGHT ANGLED
All three sides equal One right angle 90°
Pairs of Angles A B

1. COMPLEMENTARY ANGLES D
∠A and ∠B are said to be Circle
complementary if r A PARALLEL LINES
∠A + ∠B = 90° AB = Diameter (d) O
OA = OB = radius (r) d B
2. SUPPLEMENTARY ANGLES B A
∠A and ∠B are said to be d = 2 × r D
Supplementary if C
∠A + ∠B = 180° Diameter is the longest chord of any circle

Triangle Property
Sum of the lengths of any two sides is always greater than the length of the third side.