Question

Find the missing measure in each triangle with the given angle measures

Answer 1

We are asked to find the missing angle in each of the given triangles.

Recall the fact that the sum of interior angles of a triangle must be equal to 180°.

7)

`45\degree+35\degree+x=180\degree`

Let us solve the above equation for the unknown angle x.

`\begin{gathered} 45\degree+35\degree+x=180\degree \\ 80\degree+x=180\degree \\ x=180\degree-80\degree \\ x=100\degree \end{gathered}`

Therefore, the missing angle is 100°

8)

Similarly, sum the angles and equate them to 180°

`\begin{gathered} 100\degree+x+40\degree=180\degree \\ 140\degree+x=180\degree \\ x=180\degree-140\degree \\ x=40\degree \end{gathered}`

Therefore, the missing angle is 40°

9)

Similarly, sum the angles and equate them to 180°

`\begin{gathered} x+90\degree+16\degree=180\degree \\ x+106\degree=180\degree \\ x=180\degree-106\degree \\ x=74\degree \end{gathered}`

Therefore, the missing angle is 74°