Similar Triangles (A) Worksheet | PDF Printable Geometry Worksheet - Free Printable

1) A and C; AA similarity (both have angles 100° and 50°, so third angle is 30° in both).
2) A and C; AA similarity (both have angles 55° and 35°, so third angle is 90° in both).
3) A and C; SSS similarity (sides proportional: 6/4 = 8/5 = 10/6.67 ≈ 1.5, but actually 6/4=1.5, 8/5=1.6, 10/6.67≈1.5 — correction: check ratios: A sides 6,8,10; C sides 4,5,6 → 6/4=1.5, 8/5=1.6, 10/6≈1.67 — not proportional. Recheck: Actually, A: 6,8,10; B: 9,12,15 → 6/9=2/3, 8/12=2/3, 10/15=2/3 → A and B are similar by SSS. C: 4,5,6 → 4/6=2/3, 5/8=0.625, 6/10=0.6 — not same. So A and B are similar.
Correction: Triangles A and B: sides 6,8,10 and 9,12,15 → ratios 6/9=2/3, 8/12=2/3, 10/15=2/3 → SSS similarity.
4) A and C; SAS similarity (angle 25° included between sides 6 and 11 in A, and 10.2 and 18.7 in C; ratio 6/10.2=10/17≈0.588, 11/18.7≈0.588 — same ratio, so SAS).