ACT SAT Prep How to determine the perimeter of a triangle using similar triangles

The video tutorial explains a geometry problem involving parallel lines and triangle perimeters. It guides students through conceptualizing the problem by redrawing figures and understanding the relationship between side lengths and perimeters using ratios. The tutorial demonstrates how to apply proportions to solve for the perimeter of a larger triangle, emphasizing the importance of understanding similar figures and the cross product method in solving proportions.

What is the first step suggested to understand the problem of finding the perimeter of triangle PRT?

• Measure the angles of the triangles

• Find the midpoint of line QS

• Redraw the figures to visualize the problem

• Calculate the area of triangle QRS

What is the perimeter of a square with side length 2?

• 10

• 8

• 6

• 4

If a rectangle's side lengths are tripled, what happens to the ratio of side length to perimeter?

• It doubles

• It remains the same

• It triples

• It halves

How do you solve a proportion using cross multiplication?

• Multiply the numerator of one fraction by the denominator of the other

• Multiply across the fractions

• Multiply the numerators together

• Add the numerators and denominators

What is the perimeter of triangle PRT if the perimeter of triangle QRS is 11?

• 22

• 33

• 44

• 55