Proportions and Similar Triangles

The video tutorial explains how to find the value of X in similar triangles by using the property that the ratios of corresponding sides are equal. It demonstrates setting up proportions and solving for X using cross multiplication. An alternative method is also shown, confirming the same result.

What is the key property of similar triangles?

• Their corresponding angles are equal.

• Their corresponding sides are equal.

• Their areas are equal.

• Their corresponding sides are proportional.

Which of the following pairs of side lengths are corresponding in the given triangles?

• 13 and 20

• 5 and 20

• 12 and 52

• 5 and 12

What is the ratio of the sides 5 and 20?

• 1:4

• 4:1

• 1:5

• 5:1

How do you solve the proportion 5/20 = 12/X?

• Add 5 and 20, then divide by 12.

• Multiply 5 by X and 20 by 12, then solve for X.

• Divide 20 by 5, then multiply by 12.

• Subtract 5 from 20, then divide by 12.

What is the value of X when solving the proportion 12/X = 13/52?

• 52

• 13

• 48

• 12