Lya M.

asked • 09/26/22

Unit 12: Circles

Four tangents are drawn from E to two concentric circles. A, B, C and D are the points of tangency. Name as many pairs of congruent triangles as possible and tell how you can show each pair is congruent.


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Mark M.

Access is denied. Review post for accuracy of link.
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09/27/22

Doug C.

Here us a Desmos graph depicting the problem. Try enabling rows 25,29,32,35 one at a time to see if this gives you the idea. desmos.com/calculator/ya9sxkagt4 You should have some theorems like 1. Tangents to a circle from an external point are congruent. 2. Radii drawn to a point of tangency are perpendicular to the tangent 3. All radii of a circle are congruent.
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09/27/22

1 Expert Answer

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Julia Z. answered • 09/09/23

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There are at least two pairs of congruent triangles: EBO and ECO, as well as AEO and DEO, assuming that O is the center of the circles.

Additional information is required if we are limited to using only tangents and radii, or any other elements besides E, A, B, C, D, and O.

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