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QUESTION ONLY FOR GENIUSES OR PEOPLE OF HIGHER RANKS
Hey please answer my question bcoz tomorrow's my maths exam.... Question number 2 to 6
Answers
Question 3 :
Area of circle = π r^2
Take π as 22 / 7
(i) Area = 22 / 7 cm^2
= > 22 / 7 cm^2 = π r^2
= > 22 / 7 cm^2 = 22 / 7 r^2
= > r^2 = 1 cm^2
= > r = 1 cm
Answer : 1 cm
(ii) Area = 154 cm^2
= > π r^2 = 154 cm^2
= > 22 / 7 r^2 = 154 cm^2
= > r^2 = 154 cm^2 × 7 / 22
= > r^2 = 7 cm^2 × 7
= > r^2 = 49 cm^2
= > r = 7 cm
ANSWER :
7 cm
(iii) 314 + 2/7 cm^2
π r^2 = 314 + 2/7 cm^2
= > 22 / 7 r^2 = ( 314 × 7 + 2 ) / 7 cm^2
= > 22 r^2 = 2198 cm^2 + 2 cm^2
= > 22 r^2 = 2200 cm^2
= > r^2 = 2200 / 22 cm^2
= > r^2 = 100 cm^2
= > r = 10 cm
ANSWER :
10 cm
QUESTION 4 :
Area = π r^2
= π ( r/2 )^2
= π d^2 / 4 ( d = diameter )
(i) Area = 2826 m^2
= > d^2 / 4 π = 2826 m^2
= > 3.14 d^2/4 = 2826 m^2
= > d^2 = 11304 m^2 / 3.14
= > d^2 = 3600 m^2
= > d = 60 m
ANSWER :
60 m
(ii) Area = 7.065 mm^2
= > d^2 / 4 π = 7.065 mm^2
= > d^2 / 4 π = 7.065 mm^2
= > d^2 / 4 = 7.065 / 3.14 mm^2
= > d^2 / 4 = 2.25 mm^2
= > d / 2 = 1.5 mm
= > d = 3 mm
ANSWER :
3 mm
(iii) Area = 254.34 cm^2
= > d^2 / 4 π = 254.34 cm^2
= > d^2 / 4 = 254.34 / 3.14 cm^2
= > d^2 / 4 = 81 cm^2
= > d / 2 = 9 cm
= > d = 18 cm
ANSWER :
18 cm
QUESTION 5
(i)
Circumference = 88 cm
π d = 88 cm
= > 22 / 7 d = 88 cm
= > d = 88 × 7 / 22
= > d = 4 × 7
= > d = 28 cm
= > r = 28/2 = 14 cm
Area = π r^2
= 22 / 7 × 14 cm × 14 cm
= 22 × 28 cm^2
= 616 cm^2
ANSWER :
616 cm^2
(ii) Area = 15400 cm^2
= > π r^2 = 15400 cm^2
= > 22 / 7 × r^2 = 15400 cm^2
= > r^2 = 15400 cm^2 × 7/22
= > r^2 = 700 × 7
= > r^2 = 4900
= > r = 70 cm
Circumference = 2 π r
= > 2 × 22/7 × 70 cm
= > 44 × 10 cm
= > 440 cm
ANSWER :
440 cm
Question 6
Area of quadrant = 1/4 π r^2
= 1/4 × 22/7 × 7 cm × 7 cm
= > 1/4 × 22 × 7 cm^2
= > 1/4 × 154 cm^2
= > 38.5 cm^2
ANSWER :
38.5 cm^2