These activity sheets give your students practice in comparing triangles through angles, segments, and ratios.

What Are Similar Triangles? These are triangles that have the same shape, and their sizes are dynamic. With these corresponding shapes the corresponding angles will be congruent, and the side will have equal proportion when the pair of the triangle is similar. The symbol of such triangles is ~. Similar triangles formula: we can explore the sides of one triangle by another triangle. We can use the following expressions to find the valid angles and length of the sides of any two triangles; ∠A = ∠X, ∠B = ∠Y, ∠C = ∠Z, AB/XY = BC/YZ = AC/XZ Condition for the similar triangle: If you have the smallest polygon that has three sides, the condition for similar triangles is: Equal corresponding angles , Proportional corresponding sides Examples: Problem#1: We have △ ABC & △APQ, and the length of their sides are; AP= 5cm, PB= 10cm, BC= 20cm And, PQ that is parallel to BC Here, you have to find PQ. Solution: In both triangles, the angle is the same, and ∠APQ = ∠ABC are corresponding angles. △ ABC ~ △ APQ - AP/AB= PQ/BC -> (1) Putting the values in eq(1), 5/15 = PQ/20 - PQ= 20/3 cm

When we are sure that we have two triangles that are similar, you can learn the measures of all the angles and sides with a simple application. Similar triangles are the same in every way expect for size. We often mark corresponding sides and angles to tell us that those measures are equal. The goal should be to find the ratio between the corresponding sides or angles. Once you find the value of that scale, you just need to apply that proportion to calculate all of the measures. These worksheets explain how to use similar triangles to find the measure of the length of other triangles.



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Similar Triangles Lesson

This worksheet explains how to find the measure of the side of a triangle given the measurements of a similar triangle. A sample problem is solved, and two practice problems are provided.

Practice Worksheet

We learn how to apply this skill to real world word problems such as: At a certain time of the day, the shadow of a 9' boy is 14' long. The shadow of a tree at this same time is 16' long. How tall is the tree?

Practice Worksheet 2

Students will answer questions about similar geometric. Ten problems are provided.

Review and Practice

Students review how to find the length of the largest side of a triangle given the measurements of a similar shape. Six practice problems are provided.

Quiz

Students will demonstrate their proficiency finding the measure of the sides of triangles given similar triangles. Ten problems are provided.

Skills Check

An example problem for you: The sides of a triangle are 5, 12 and 11. Find the length of the longest side of a similar triangle whose shortest side is 16.

Finding the Sides of Similar Triangles Basic Skills

Students will find the measure of a specified side of a triangle, based on what is known about a similar shape. Ten problems are provided.

Basic Skills Review

Write three equal ratios to show corresponding sides are proportional. Ten problems are provided.

Finding the Lesson

This worksheet explains how to find the measure of a specified side of a triangle, based on what is known about a similar triangle. A sample problem is solved.

Lesson and Practice

This worksheet reviews how to find the measure of a specified side of a triangle, based on what is known about a similar triangle. A sample problem is solved, and two practice problems are provided.

Finding the Sides Worksheet

Students will find the measure of a specified side of a triangle, based on what is known about a similar triangle. Ten problems are provided.

Practice Worksheet

Write the ratio of the given corresponding sides, find the value of unknown sides. Ten problems are provided.

Similar Triangles Drill

Students will find the measure of a specified side of a triangle, based on what is known about a similar triangle. Eight problems are provided.

Warm Up

Students will find the measure of a specified side of a triangle, based on what is known about a similar triangle. Three problems are provided.

Intermediate Skills

Students will solve slightly more complicated problems using similar triangles. Ten problems are provided.

Similar Triangles Intermediate Skills Review

Based on what is known about a similar triangle, students will find the measure of a specified side of a triangle. Ten problems are provided.

Intermediate Skills Drill

Students will use similar triangles to find the measure of a specified side of a triangle. Ten problems are provided.

Similar Triangles Lesson

This worksheet explains how to find the side of a triangle based on a similar triangle. A sample problem is solved, and two practice questions are provided.

Class Worksheet

Students will find the side of a triangle based on a similar triangle. Ten questions are provided.

Practice Worksheet

Students will use a similar triangle to find the indicated side of another triangle. Ten questions are provided.

Review and Practice

This worksheet review how to find the side of a triangle based on a similar triangle. Six practice questions are provided.

Skill Quiz

Students will demonstrate their proficiency finding the missing sides of triangles based on what they have learned. Ten problems are provided.

My Triangles Check

See how well you have mastered this skill and take it to the next level. Space is included for students to copy the correct answer when given.

Find the Missing Sides Lesson

This worksheet explains how to find the missing sides. Using the given information, rewrite the equation by substituting the respective value in it. A sample problem is solved.

Lesson and Practice

This worksheet reviews how to apply this skill to real world problems. Example exercise: You are 160 m tall. At a certain time of a day, your shadow is 75 m long. The shadow of a tree is 190 m long. How tall is the tree? A sample problem is solved, and two practice problems are provided.

Find the Missing Sides Worksheet

Students will find the missing sides of two similar triangles. Ten descriptions are provided.

Practice Worksheet

Given coordinate points, students will find the missing sides of two similar triangles. Ten problems are provided.

Skill Drill

Students will find the missing sides of a series of triangles. Eight problems are provided.

Warm Up

Students will find the missing sides of two similar triangles. Three problems are provided.