Question

Triangle ABC is similar to DEF. Which proportion can be used to find the length of DE in centimeters?

Answer 1

`(DE)/(4) = (9)/(3)`

`DE = 12`

Explanation:

Given

See attachment for triangles ABC and DEF

Required

The proportion to find DE

To solve for DE, we can make use of the following equivalent ratios;

`AB:DE = BC:EF`

Substitute values for AB, BC and EF

`4:DE = 3:9`

Express as fractions

`(DE)/(4) = (9)/(3)`

The above is the proportion to solve for DE

Solving further:

`(DE)/(4) = 3`

`DE = 4 * 3`

`DE = 12`