Find the Side Ratio: Comparing Triangles ABC and MNA in Geometric Analysis

Question

AAABBBCCCMMMNNN36 What is the ratio between the sides of the triangles ΔABC and ΔMNA?

Video Solution

Solution Steps

00:00 Find the similarity ratio
00:03 Equal angles according to given data
00:07 The triangles share the same vertex angle
00:15 Similar triangles by AA
00:24 Let's find the similarity ratio
00:30 Similarity ratio is always the side opposite to the equal angle
00:41 We'll substitute appropriate values according to the given data and solve for the ratio
00:49 And this is the solution to the question

Step-by-Step Solution

From the data in the drawing, it seems that angle M is equal to angle B

Also, angle A is an angle shared by both triangles ABC and AMN

That is, triangles ABC and AMN are similar respectively according to the angle-angle theorem.

According to the letters, the sides that are equal to each other are:

ABAM=BCMN=ACAN \frac{AB}{AM}=\frac{BC}{MN}=\frac{AC}{AN}

Now we can calculate the ratio between the sides of the given triangles:

MN=3,BC=6 MN=3,BC=6 63=2 \frac{6}{3}=2

Answer

BCMN=2 \frac{BC}{MN}=2