![m\angle K= 56^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/g2d91xam8l3vya9md121wisz26jrc0v7r6.png)
Explanation:
Step 1:
The total of the angles in any triangle is 180°.
So to determine the third angle of the given triangles, we subtract the sum of the other two sides from, 180°.
The third angle = 180° - (the first angle + the second angle).
Step 2:
For triangle ABC,
,
![m\angle B=180^(\circ)-(83^(\circ) + 56^(\circ)) = 180^(\circ) - 139^(\circ) = 41^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/6kdhy03h42597yi4wy8o7qolisirdm7pka.png)
So
![m\angle B= 41^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/vikfp70ttd6m8xb6dz153xfyhlfa1lzkhu.png)
For triangle DEF,
,
![m\angle F=180^(\circ)-(61^(\circ) + 49^(\circ)) = 180^(\circ) - 110^(\circ) = 70^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/9c5l5hfrllp95vbump3b79x3o50wnow4ki.png)
So
![m\angle F= 70^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/51jbru0vhvfum3z2tfbss2rs6s1z2c2mhq.png)
Step 3:
For triangle GHI,
,
![m\angle H=180^(\circ)-(49^(\circ) + 70^(\circ)) = 180^(\circ) - 119^(\circ) = 61^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/bvzviq3njxxiayn627rq0u8jmvw7w5h503.png)
So
![m\angle H = 61^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/yutul9p4od9fqzkuwvoxbxkeagycbtdh28.png)
For triangle JKL,
,
![m\angle K=180^(\circ)-(83^(\circ) + 41^(\circ)) = 180^(\circ) - 124^(\circ) = 56^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/xr6jqtsdiqwva0nu3kvmie7q56ys97m3gu.png)
So
![m\angle K= 56^(\circ).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/g2d91xam8l3vya9md121wisz26jrc0v7r6.png)