BRAINLIEST 50 POINTS!!! 1. Rihanna wants to find the distance, AB, across a river. She starts at point B and walks along the edge of the river 215 ft and marks point C. Then she walks 25 ft further and marks point D. She turns 85° and walks until her final location and marks point E. Point E, point A, and point C are collinear.

A. The Angle-Angle theorem can be used to conclude that triangle ABC and triangle EDC are similar. The Angle-Angle Theorem requires that the prover knows two angles that are equal to each other thus guaranteeing that the third angle is equal meaning that the triangle is similar.

In this case, we know Angle EDC and Angle ABC are equal. And also, since Angle DCE and Angle ACB are vertical angles, that means they are equal to each other. Thus we have fulfilled the Angle-Angle Theorem proving that triangle ABC and triangle EDC are similar.

B. We now know that DE is 105 ft. Since triangle ABC and triangle EDC are similar, that means that all their corresponding sides are proportional, thus we get the equations:

[tex]\frac{25}{215} =\frac{105}{AB} \\\\25AB = 105*215\\\\AB = 903ft\\\\[/tex]

Thus AB is 903 ft