In a quadrilateral, the angles are$\mathrm{x}°,\left(\mathrm{x}+10\right)°,\left(\mathrm{x}+20\right)°$  and $\left(\mathrm{x}+30\right)°$, then the measure of greatest angle is

$\mathrm{x}°,\left(\mathrm{x}+10\right)°,\left(\mathrm{x}+20\right)°,\left(\mathrm{x}+30\right)°$
$\begin{array}{l}{\mathrm{x}}^{\circ }+(\mathrm{x}+10{)}^{\circ }+(\mathrm{x}+20{)}^{\circ }+(\mathrm{x}+30{)}^{\circ }={360}^{\circ }\\ \Rightarrow 4{\mathrm{x}}^{\circ }+{60}^{\circ }={360}^{\circ }\\ \Rightarrow 4{\mathrm{x}}^{\circ }={360}^{\circ }-{60}^{\circ }\\ \Rightarrow 4{\mathrm{x}}^{\circ }={300}^{\circ }\\ \Rightarrow {\mathrm{x}}^{\circ }={75}^{\circ }\\ (\mathrm{x}+10{)}^{\circ }={75}^{\circ }+{10}^{\circ }={85}^{\circ }\\ (\mathrm{x}+20{)}^{\circ }={75}^{\circ }+{20}^{\circ }={95}^{\circ }\\ (\mathrm{x}+30{)}^{\circ }={75}^{\circ }+{30}^{\circ }={105}^{\circ }\end{array}$
The greatest angle is 105°