Answer:
6) x = 16°, scalene triangle
7) x = 45°, right triangle
Step-by-step explanation:
The sum of all angles within a triangle is 180 degrees so if given two angles, we can set up an equation to solve for the missing third angle.
For question 6, our equation is 39 + 125 + x = 180. Let's solve and then classify:
39 + 125 + x = 180
164 + x = 180
164 - 164 + x = 180 - 164
0 + x = 180 - 164
x = 16
Because no two angles within the triangle have the same measure and no two legs on its edges have the same length, its classification is a scalene triangle.
For question 7, the triangle has a box that indicates one of its known angles is 90 degrees. So our equation is 90 + 45 + x = 180. Let's solve and then classify:
90 + 45 + x = 180
135 + x = 180
135 - 135 + x = 180 - 135
0 + x = 180 - 135
x = 45
Because the triangle contains a right angle indicated by that same box we used to derive that one of the angles measured 90 degrees, we can determine that this classification is a right triangle.