Question

Two sides of a triangle measure 18 meters and 11 meters. If the perimeter of the triangle is 37 meters, what is the length of the third side?12 m8 m66 m30 m

Answer 1

Since the triangle has 3 sides, then

The perimeter of the triangle is the sum of the lengths of the 3 sides

$P=s_1+s_2+s_3$

Since the perimeter is 37 meters, then

$P=37$

Since the lengths of 2 sides are 18 meters and 11 meters, then

$\begin{gathered} s_1=18 \\ s_2=11 \end{gathered}$

Substitute them in the rule above

$\begin{gathered} 37=18+11+s_3 \\ 37=29+s_3 \end{gathered}$

Subtract 29 from both sides

$\begin{gathered} 37-29=29-29+s_3 \\ 8=s_3 \end{gathered}$

The length of the 3rd side is 8 meters

The answer is the 2nd choice