question 1



 Oct 11, 2018

Angle FED and CEB are vertical angles and therefore congruent. 
Angle EDF and ECB are both right angles and there congruent.

Using the AA Similiarity Postulate, we can say that triangles FED and BEC are similar.

Now, we can use the idea that corresponding sides of similar triangles are proportional to find DF. 
First, we know that the sides of the square have lengths of  7 as DE = 2 and EC = 5, so DC = 7.
So, side BC = 7 as well.
Set up a proportion:
\(\frac{DE}{CE}=\frac{DF}{CB}\\ \frac{2}{5}=\frac{DF}{7}\\ \frac{14}{5}=DF\)
DF = 14/5 or 2.8

 Oct 11, 2018

Thank you guest, also I feel that it is not AA Similarity Postulate but AA Similarity Criterion. Just my opinion about it

 Oct 11, 2018

10 Online Users

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.