For the first one, we know that is a right angle. right angles are 90 degrees. if we subtract 90 - 49 that equals 41. so the second value needs to equal 41. since we have a 3 there already, we are going to subtract 41-3, which is 38. x = 38

3 0

3 years ago

The empty gas tank of a motor boat is to be filled. The tank is shaped like a rectangular prism with length 20 cm, width

Minchanka [31]

Answer:

Step-by-step explanation:

8 0

2 years ago

1)a chord of length 18cm midway the radius of a circle. calculate the radius of the circle correct to 1d.p. 2)if two parallel ch

kykrilka [37]

Part 1:

Given that the length of the chord is 18 cm and the chord is midway the radius of the circle.

Thus, half the angle formed by the chord at the centre of the circle is given by:

$\cos\theta=\frac{\left( \frac{1}{2} r\right)}{r}= \frac{1}{2} \\ \\ \Rightarrow\theta=\cos^{-1}\left( \frac{1}{2} \right)=60^o$

Now,

$\sin60^o= \frac{9}{r} \\ \\ \Rightarrow r= \frac{9}{\sin60^o} =10.392$

Therefore, the radius of the circle is 10.4 cm to 1 d.p.

Part 2I:

Given that the radius of the circle is 10 cm and the length of chord AB is 8 cm. Thus, half the length of the chord is 4cm. Let the distance of the mid-point O to /AB/ be x and half the angle formed by the chord at the centre of the circle be θ, then

$\sin\theta= \frac{4}{10} = \frac{2}{5} \\ \\ \theta=\sin^{-1}\left( \frac{2}{5} \right)=23.6^o$

Now,

$\cos23.6^o= \frac{x}{10} \\ \\ \Rightarrow x=10\cos23.6^o=9.165\approx9.2cm$

Part 2II:

Given that the radius of the circle is 10cm and the angle distended is 80 degrees. Let half the length of chord CD be y, then:

$\sin40^o= \frac{y}{10} \\ \\ \\ \Rightarrow y=10\sin40^o=6.428$

Thus, the length of chord CD = 2(6.428) = 12.856 which is approximately 12.9 cm.

3 0

3 years ago

I need helpp...........

Rama09 [41]

Answer:

Step-by-step explanation:

(2 x 6) + ( $\sqrt{16\\}$ - 8 ÷ 2^2) =

12 + (4 - 8 ÷ 4)

12 + (4 - 2)

12 + 2

5 0

2 years ago

True or False: If circumference of a circle is 12*3.14, then its area is 36*3.14.

True or False: If circumference of a circle is 123.14, then its area is 363.14.