Now use the information you already have about finding the equation of a line and apply it to the dashed lines shown in these triangles. Remember, to find the equation of a line you need a point ...

Calculate missing angles in triangles, ... Applying the properties of shapes to determine an angle Perpendicular bisector. Angles in a triangle add up to 180° and quadrilaterals add up to 360°.

In the triangle above, segment BD is an angle bisector. Sides AB = 9x − 14, BC = 4x − 3, CD = 2x + 11 and AD = 5x + 2. Find the area of triangle ABD and the measure θ .