Slope, Ratio, and Similar Triangles

​Slope & Triangles

By Kathryn Yue

Open Ended

What are some words you think of when you think of triangles?

The steepness of a line

​​Slope

A comparison of two quantities

​​Ratio

Multiple Choice

Which definition describes slope?

• Slope is the measure of the area enclosed by a curve.
• Slope is the distance between two points on a line.
• Slope is the angle between two intersecting lines.
• Slope is the ratio of the vertical change to the horizontal change between two points on a line.

How do I identify similar sides of a triangle?

​Identify the similar sides of Triangle DEF.

Can you write the ratio comparing the two triangles using the side length description?


Yellow = rise

Pink = run

​Write the ratio that represents the slope.

Multiple Choice

In the slope-intercept formula, which letter represents the y-intercept?

• y

• m

• x

• b

Multiple Choice

When given two similar triangles on the same line, they will ALWAYS have the same _______________?

• y-intercept

• x

• slope

• y

Multiple Choice

Are the two ratios equivalent?

• YES

• NO

Multiple Choice

Select the triangle that could lie on a line with a slope of 3/2.

Multiple Choice

What is the slope that can be made from this slope triangle?

• 1/3

• 3

• 20

• 1/20

Multiple Choice

Identify the slope (AC) of triangle ABC.

• 2

• 1/2

• -2

• -1/2

Multiple Choice

What is the slope of the line?

• 2

• 3

• 2/3

• 3/2

Open Ended

How are ratios of similar triangles related to the slope of the line?