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Home > CC2MN > Chapter 4 > Lesson 4.4.2 > Problem 4-140

4-140.

Two similar triangles are labelled A, B, C and D, E, F. The side opposite angle A is x, opposite angle B is y and opposite angle C is 8 feet. The side opposite angle D is 3 feet, opposite angle E is 4 feet and opposite angle F is 5 feet. and are similar.  

Find the scale factor between the two corresponding sides that are given and utilize it with the respective side lengths from   to get and .

The scale factor is .

  1. Find .

  2. Find .

  3. Find the ratio of the perimeters of the two triangles.

    Find the perimeters of both triangles and compare them as a ratio. What do you notice?

    Perimeter of :  ft
    Perimeter of  ft

  4. Can you predict the ratio of the areas of the two triangles? If so, state it. If not, write the information you would need or the question you would need to answer first.

    According to the Math Notes box from Lesson 4.4.2:

    The area ratio is .

    Try predicting the area ratio of the two triangles. What do you get?

  5. A triangle where the vertices are labelled R, S, and T. Angle S is 53 degrees.  Angle R is 37 degrees. Triangle is congruent to triangle . Based on this, what are the side lengths of triangle ? What is the measure of angle ?

    Examine the two triangles and the corresponding sides or angles to determine each measure.