Linear Equations and Inequalities

Question

In an isosceles triangle, there are two sides, called legs, that are the same length. The third side is called the base. If an isosceles triangle has perimeter 345 cm and base length 85 cm, what is the length of the each leg?

Answer 1

P= L+L+B (two equal legs along with the base)

345 = 2L + 85 (substitute and combine L + L = 2L)

2L = 260 (subtraction property for equality [345-85), and symmetric property for equality (if a=b, b = a)

L = 260/2 = 130 (division property for equality)

Check:

130+130+85 = 260+85 = 345