Question

I need help understanding

Answer 1

`\text{The angle indicated by a square shape in the figure indicates }90^o. \text{ And the two}\\\text{angles }6x\text{ and }4x+10^o\text{ on addition, gives 90}^o.\\\therefore\ 6x+4x+10^o=90^o\\\text{or, }10x=80^o\\\text{or, }x=8^o`