Ms. Warren had each student take 3 pencils and create a triangle with them. Roberto has 3 pencils that measure 12 cm, 5 cm, and 7 cm. How many triangles can Roberto create with his 3 pencils?
A. infinitely many
B. two
C. one
D. none

What is the next step in the given proof? choose the most logical approach. a. statement: m 1 + m 2 + 2(m 3) = 180° reason: angle addition b. statement: m 1 + m 3 = m 2 + m 3 reason: transitive property of equality c. statement: m 1 = m 2 reason: subtraction property of equality d. statement: m 1 + m 2 = m 2 + m 3 reason: substitution property of equality e. statement: 2(m 1) = m 2 + m 3 reason: substitution property of equality