3.0 NOT SURE IF ITS CORRECT
Answer:
160
Step-by-step explanation:
The measure of an arc is always twice the degree of the corresponding angle inside the circle. For example, the measure of arc DC is just double the measure of angle DOC; angle DOC is 44 degrees, so arc DC must be 88 degrees.
Angle COB is 80 degrees, so arc CB is 160 degrees.
The question is unclear to me, 30x3=10 WHAT, 30x3=90 not 10
And also it seems you already know the answer Perimeter=28cm
The magnification is 0.54
Given,
The distance between object and concave lens, u = -21 cm
Focal length of the concave lens, f = -25 cm
Let m be the magnification.
m = v/u
Here v is the position of image.
We have to find v first.
By using lens equation we can determine v.
That is,
1/f = 1/v – 1/u
So,
- (1/25) = 1/v – (-1/21)
- (1/25) = 1/v + 1/21
1/v = - (1/25) – 1/21
1/v = (-25 – 21) / (21 x 25)
1/v = - (46/525)
Therefore v = - (525/46)
v = -11.41 cm
Now we have to find magnification, m.
m = v/u
= (-11.41) / (-21)
= 0.54
Here magnification is 0.54
Learn more about concave lens here: brainly.com/question/12944945
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