Answer:
You could use the Pythagnerum Theorem
Step-by-step explanation:
Answer:
The radius of the circle P = 2√10 = 6.325
Step-by-step explanation:
∵ AB is a tangent to circle P at A
∴ (AB)² = BC × BE
∵ BC = 8 , AB = 12 , ED = 6
∵ BE = ED + DC + CB
∴ BE = 6 + CD + 8 = 14 + CD
∴ (12)² = 8 × (14 + DC) ⇒ (12)²/8 = 14 + CD ⇒ CD = (12)²/8 - 14
∴ CD = 4
Join PC and PE (radii)
In ΔBDC and ΔPDE ⇒ ∵ ∠PDC = Ф , ∴ ∠PDE = 180 - Ф
Use cos Rule:
∵ r² = (PD)² + (DC)² - 2(PD)(DC)cosФ
∴ r² = 16 + 16 - 32cosФ = 32 - 32cosФ ⇒ (1)
∵ r² = (PD)² + (DE)² - 2(PD)(DE)cos(180 - Ф) ⇒ cos(180 - Ф) = -cosФ
∴ r² = 16 + 36 + 48cosФ = 52 + 48cosФ ⇒ (2)
∵ (1) = (2)
∴ 32 - 32 cosФ = 52 + 48cosФ
∴ 32 - 52 = 48cosФ + 32cosФ
∴ -20 = 80cosФ
∴ cosФ = -20/80 = -1/4
∴ r² = 32 - 32(-1/4) = 32 + 8 = 40
∴ r = √40 = 2√10 = 6.325
Answer:
Kian's method is correct.
Step-by-step explanation:
Javine says, "To multiply by 1000, I just add three zeros." He is incorrect.
Kian says, "I times by 10, then times by 10 and times by 10 again. When he multiply 1 by 10, it becomes 10. Then if he again multiply by 10, it becomes 10×10 = 100. And at last when he multiply again 10, it becomes 100×10 = 1000. It means Kian's methods for multiplying by 1000 is correct.
The answers are 1/5,2/5,3/5,and 4/5
Answer:
π(6 cm) (10 cm)
Step-by-step explanation:
As we know that
The formula to calculate the lateral surface area of the cone is πrl
where
r denotes the radius i.e. 6 cm
l denotes the length i.e. 10 cm
So based on the above information
The expression that shows the lateral surface area of the cone is
π(6 cm) (10 cm)
Therefore the third option is correct
Hence, the same would be relevant
