Unit 3, Lesson 5

Splitting Triangle Sides with Dilation (Part 1)

Geometry

Practice

What is the measure of angle ?

Triangle is formed by connecting the midpoints of the sides of triangle . The lengths of the sides of are shown. What is the length of ?

Angle is taken by a dilation with center and a scale factor of to angle . The measure of angle is . What is the measure of angle ?

Draw 2 lines that could be the image of line by a dilation. Label the lines and .

Is it possible for polygon to be dilated to figure ? Explain your reasoning.

Triangle is scaled, and the image is . Write 2 equations that could be used to solve for .

Lin is using the diagram to prove the statement, “If a parallelogram has one right angle, it is a rectangle.” Given that is a parallelogram and angle is a right angle, write a statement that will help prove that angle is also a right angle.
Han then states that the 2 triangles created by diagonal must be congruent. Help Han write a proof that triangle is congruent to triangle .