Randee draws these two triangles with lengths given in centimeters. What scale factor does she use to create the copy on the right from the original on the left?

Question

1/2
2
1 1/3
1 2/3

first one is 10 inches, 15 inches, and 18 inches

second one is 20 inches, 30 inches, and 36 inches

Answer 1

To determine the scale factor Randee used to create the copy of the triangle, we need to compare the corresponding sides of the original triangle on the left with the sides of the triangle on the right.

The lengths of the original triangle are:

• 10 inches
• 15 inches
• 18 inches

The lengths of the copied triangle are:

• 20 inches
• 30 inches
• 36 inches

To find the scale factor, we can divide the side lengths of the new triangle by the side lengths of the original triangle:

1. For the first side: \[ \frac{20 \text{ inches}}{10 \text{ inches}} = 2 \]

2. For the second side: \[ \frac{30 \text{ inches}}{15 \text{ inches}} = 2 \]

3. For the third side: \[ \frac{36 \text{ inches}}{18 \text{ inches}} = 2 \]

As we can see, in each case the scale factor is 2.

Thus, the scale factor Randee used to create the copy on the right from the original on the left is 2.