Math, asked by techySayan, 10 months ago

Please help me solve out the subpart (iii) and (iv) of the question in the image.

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Answers

Answered by vvijay385
1
Solution:
FOR QUESTION (III)
In ∆OAB,
OB = OA = Radius of the circle.
Therefore, we can say that ∆OAB is an isosceles triangle.
Therefore,
Angle OBA = Angle OAB = (180-140)/2 = 20°

Hence, Angle OAB = 20°

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FOR QUESTION (IV)
Consider ∆OAC,
OA = OC = Radius of the circle.
Therefore, we can say that ∆OAC is an isosceles triangle.
Angle OBA = Angle OAB = 50°
Therefore, Angle AOC = 180-50-50 = 80°

Now, in ∆OBC,
Angle BOC = 140-80 = 60°
Since, Angle OBA = 20°
Angle OBC = Angle OBA + Angle CBA .......(1)
= (20 + x)° .........(say angle CBA = x°)
Also OB = OC = Radius of the circle.
Therefore, we can say that ∆OBC is an isosceles triangle.
Therefore, we can say that,
Angle OBC = Angle OCB = (20+x)°
We know that a triangle has 180°angle,
Therefore,
Angle BOC = Angle OBC = Angle OCB = 180°
or 60° + (20+x)° + (20+x)° = 180°
or 60 + 40 + 2x = 180
or x = 80/2
or x = 40°
Therefore,
Angle OBC = Angle OCB = 20+40 = 60° ........(2)
Therefore, Angle CBA = 40° .......(From (1) & (2))

Hence, Angle CBA = 40°

techySayan: Thanks a lot....you worked so hard to even explain me.....
vvijay385: It's my pleasure to help anyone in mathematics.
techySayan: Please try me helping me in the other questions......I would like asking in this comment section itself.....
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techySayan: This question please : The midpoints of the sides of a triangle are (-3,2), (1,-2) and (4,5) respectively. Find the coordinates of the vertices of the triangle. You need not explain, I'll be able to understand the steps. Please
vvijay385: Sure, but I'll be able answer after 30 min...
vvijay385: Answer is (-6,-5), (0,9) and (8,1). We will have to use mid point formula which gives us 6 equations viz., (x1+x2)/2=-3, (x1+x3)/2=1, (x2+x3)/2=4, (y1+y2)/2=2, (y1+y3)/2=-2, and (y2+y3)/2=5. on solving this 6 equations we will get our values
techySayan: Thanks a lot!
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Answered by Rohankaitake007
2

Answer:

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