Question

PLEASE HELP ME, I need HELP

Answer 1

15. Since l is tangent line, then angle c is right and
`c=90^(0)`;
a is twice bigger than
`20^(0)`, then
`a=40^(0)`;

`b=360^(0)-180^(0)-40^(0)=140^(0)`
19.
`b+72.5^(0)+22.5^(0)=180^(0)`,

`b=85^(0)` and
`a=180^(0)-85^(0)=95^(0)`
20. 5×15=6×(6+x), 75=36+6x, 6x=39, x=7.5