QUADRILATERALS
QUADRILATERALS
QUADRILATERAL
ParallelogramTrapezoidTrapezium
RectangleRhombus
Square
EXERCISESEXERCISES
422 = 832 + 682 -2(68)(83)CosΘ
Θ = 30.27Ο
(COSINE LAW)
30.27Ο + β = 180ο30.27Ο + β = 180ο
β = 149.73ο
d22 = 832 + 682 -2(83)(68)Cos149.73ο
d2 = 148.81 cm
d2
(COSINE LAW)
A = ½ d 1d2132cm2 = ½ (12 cm)d 2132cm2 = ((6cm)d 2)
6 cm 6cm d2 = 22 cm
(Area of
Rhombus)
Pythagorean
s = √ (11)2 + (6)2
Pythagorean
Theorem
ο
tan 60Ο = h / 3h = 5.2 cm
A = 1 / 2 (a + b) hA = 1 / 2 (8 + 11) (5.2)A = 49.4 cm2
ο
(SOHCAHTOA)
(Area of Trapezoid)
cos 60 = 3 / cc = 6 cm
A = 49.4 cm2
P = 8 + 11 +5.2 + 6P = 30.2 cm
(SOHCAHTOA)
(Perimeter)
s = 10 + 5 + 14.14 + 152
s = 22.07 cm
A = √ (s-a)(s-b)(s-c)(s-d) - abcd cos 2 [½(A+C)]
A =√(22.07-10)(22.07-5)(22.07-14.14)(22.07-15) – (10)(5)(14.14)(15) cos 2 [½(225)]
A = √(12.07)(17.07)(7.93)(7.07) – (10)(5)(14.14)(15) cos 2 [½(225)]
A = 99.9 m2
(General Formula for Area of Quadrilaterals)