If AB = 9, RS = 3, and SC = 5, find BC.
A) 5
B) 10
C) 13.5
D) 15

Answer:
D
Step-by-step explanation:
Δ ABC and Δ RSC are similar triangles, thus the ratio of corresponding sides are equal, that is
[tex]\frac{BC}{SC}[/tex] = [tex]\frac{AB}{RS}[/tex], substitute values
[tex]\frac{BC}{5}[/tex] = [tex]\frac{9}{3}[/tex] = 3 ( multiply both sides by 5 )
BC = 5 × 3 = 15 → D
Answer:
BC=15, so D
Step-by-step explanation:
First, let's annotate. on line AB, write 9. RS, 3. SC, 5. These are the measurements of lines, not angles. We're trying to find the length of BC, the whole bottom side. Also, all of the little squares represent 90° angles, which means the triangles are also rational.
I REALLY hope this helps. If not, I encourage you to watch videos on dilations/rational triangles.