Step-by-step explanation:
your teacher was very nice and warned you about the trap in the question.
so, really, what do we have to do ?
a full circle represents 360°.
the shaded sector is the full circle minus the white sector !
this is the same as directly calculating the shaded sector for 360-75 = 285°.
so, the area of a circle is
pi×r²
in our case
pi×20² = 400pi
the needed fraction of the whole circle is either
75/360, if we want to subtract it for the solution
or
285/360, if we want to calculate the solution directly.
both lead to the same result.
400pi×360/360 - 400pi×75/360 =
= 400pi × 285/360 = 10pi × 285/9 = 2850pi/9 =
= 316.6666666...pi ≈ 316.7pi
Answer: B
Step-by-step explanation:
(I tried)
The formula for the area of a circle is <u>A (area) = π (3.14) x R (radius) ^2 </u>(second power)
Since the word problem gave the diameter, you can divide that by 2 to give you 9, aka the radius. (Radius + Radius = Diameter, diameter divided by 2 gives you radius)
Looking back at the formula, R^2 (it always comes first), 9^2 (9x9) equals 81 and then multiplying pi (3.14) to get your answer of 254.34 in.
1. you can cut this in half to make a 2 by 3 rectangle and a 2 by 2 square. 2 times 2 is 4. 2 times 3 is 6. 6 plus 4 is 10 which is the area.
2. same thing but its 3 shapes.
3. well 7 times 7 is 49 so 7 times 6 if 42 so 6 weeks.
4. 1/4
5. 7:45
6. 10 kilos.
Answer:
(x, y) ⇒ (2x, 2y)
Step-by-step explanation:
Transformation is the movement of a point from its initial location to a new location. Types of transformation are reflection, translation, rotation and dilation.
Dilation is the increase or decrease in size of a figure. If a figure with point A(x, y) is dilated by a scale factor of k, the new location is at A'(kx, ky). If k > 1, it is an enlargement and if k < 1, it is a reduction.
Given that the inner circle has a radius of 1 r and the outer one has a radius of 2 r. To map the inner circle onto the outer circle, the inner circle would need to be enlarged. The scale factor is:
k = outer circle radius / inner circle radius = 2r / 1r = 2
A dilation with a scale factor of 2 would be needed to map the inner circle onto the outer circle.
That is:
(x, y) ⇒ (kx, ky)