Question

1 Three triangles are shown 60 Triangle R Tangles mlangle T The measure of the exterior angle shown is represented by x in each triangle. Which of the following represents the correct order of the triangles from least to greatest, if the order is based on? 5 1

Answer 1

We know that all intern angles of a triangle must add up 180°, then:

For Triangle R:

$\begin{gathered} 45+90+y=180 \\ y=180-135=45 \\ So, \\ x=180-45 \\ x=135 \end{gathered}$

For triangle S:

$\begin{gathered} 60+90+y=180 \\ y=180-90-60 \\ y=30 \\ So, \\ x=180-30 \\ x=150 \end{gathered}$

For triangle T:

$\begin{gathered} 60+60+y=180 \\ y=180-60-60 \\ y=60 \\ So, \\ x=180-60 \\ x=120 \end{gathered}$

Therefore, the correct order of triangles from least to greatest based on x is:

T, R and S.

Correct answer is B.