Question

of the angles of a triangle are shown in the figure below. solve

Explanation:

Step1: 依据三角形内角和定理

$108^{\circ}+47^{\circ}+(2x + 11)^{\circ}=180^{\circ}$

Step2: 化简方程左边

$108 + 47+2x+11=166 + 2x$，则$166 + 2x=180$

Step3: 求解x

$2x=180 - 166$，即$2x = 14$，$x = 7$

Step4: 求未知角的度数

把$x = 7$代入$2x + 11$，得$2\times7+11=25^{\circ}$

Answer:

$x = 7$，未知角为$25^{\circ}$