Tangents With Letters

Part of the Circles section of Coddy's Geometry journey. Lesson 51 of 62.

When a tangent's length is an expression, the equal tangents rule gives an equation: the two labels are equal.

$Tangents from P of x plus 4 and 10$

Here PT = x + 4 and PU = 10. The tangents are equal, so x + 4 = 10 and x = 6. Tap the two tangents and pick Tangents from a point; the board writes the equation for you.

Challenge

PT and PU are tangents from P to circle O. Tap the two tangents, pick the rule that connects them, and solve the equation the board writes for x.

Then press Check.

Try it yourself

$Use the figure to find x$

Use the figure to find x

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Circles

1Parts of a Circle

Center and Radius Chords and Diameters All Radii Are Equal Diameter Is Two Radii Recap: Parts of a Circle

4Arcs and Sectors

Arc Length Area of a Sector Find the Central Angle The Missing Central Angle Recap: Arcs and Sectors

7Angles in a Semicircle

Thales' Theorem The Right Angle Inside Is That Enough?Semicircle With Letters Recap: Semicircles

10Tangents

What a Tangent Is Tangent and Radius Tangent Lengths Two Tangents From a PointTangents With LettersRecap: Tangents