The longest of a triangle is 10cm. which group of line segments could form the other 2 sides of the triangle? HELP PLEASE

A 9cm and 10
B 7cm and 8cm
C 5cm and 5cm
D 4cm and 4cm​

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

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

Layla answer 21 of the 25 questions on his history test correctly.what decimal represents the fraction of problem he answer incorrectly.