Question

To draw a pair of tangents to a circle which are inclined to each other at an angle of 80o, it
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Answer 1

Answer:

Method 1:

Construct a circle concurrent with the other circle with radius 80°.

And construct two tangents of the older circle from any point on the circle, the angle between them will be csc 40°

using trigonometry, we can find that the distance between the centre of the circle and the point where the tangents meet will be 120°.

Method 2:

Construct 2 radius with an angle of between them.

And draw perpendiculars from their point of contact. When these perpendiculars meet, they'll meet at 80°

the tangents are perpendicular to radius at point of contact. So, inorder to satisfy angle sum property, the other two angles should be supplementary; and supplementary angle of 80 ° is 120° .