Worked examples
Two examples
Example 1
Two triangles are similar. A side of 4 in the small one matches a side of 10 in the large one. Another side of the small one is 6. What is its match?
- The scale factor is 10 ÷ 4 = 2.5.
- 6 × 2.5.
Answer: 15
Example 2
Two similar rectangles: the small one is 3 by 5, and the large one is 9 by ?.
- The scale factor is 9 ÷ 3 = 3.
- 5 × 3.
Answer: 15
Where this is taught: Quiz 37: Similar Figures, “The scale factor”
The drill
Ten problems
This drill also has challenge problems. They use the same skill, set up the way the GED test sometimes sets up a problem, so that it looks new at first.
How many:
Type each answer, then press Check my answers at the bottom. Commas in large numbers are fine.Write each answer on the line. The answer key, with the reasoning, is on the last page.