ABCD is a trapezium with ab parallel to dc and angle abc is equal to 90 degree BC is a quadrilateral of a circle if BC = CD = 4.2 cm and ae = 1.8 cm find the area of shaded region
Answers
Answer:
ANSWER
Given: CE=CB=7cm
∴ CD=CE+ED=(7+4)cm=11cm
In Δ CLB, we have
sin60
∘
=
BC
BL
⇒
2
3
=
7
BL
⇒BL=
2
7
3
cm
∴ Area of trapezium =
2
1
(AB+CD)×BL=
2
1
(7+11)×
2
7
3
cm
2
=
2
63
3
cm
2
Area of sector BFEC =
360
∘
60
∘
×
7
22
×7
2
cm
2
=
3
77
cm
2
.......(Area of sector=
360
θ
×πr
2
)
∴ Required area = (
2
63
3
−
3
77
)cm
2
=(54.558−25.666)cm
2
=28.89cm
2
Step-by-step explanation:
Given: CE=CB=7cm
∴ CD=CE+ED=(7+4)cm=11cm
In Δ CLB, we have
sin60
∘
=
BC
BL
⇒
2
3
=
7
BL
⇒BL=
2
7
3
cm
∴ Area of trapezium =
2
1
(AB+CD)×BL=
2
1
(7+11)×
2
7
3
cm
2
=
2
63
3
cm
2
Area of sector BFEC =
360
∘
60
∘
×
7
22
×7
2
cm
2
=
3
77
cm
2
.......(Area of sector=
360
θ
×πr
2
)
∴ Required area = (
2
63
3
−
3
77
)cm
2
=(54.558−25.666)cm
2
=28.89cm
2