Question

4. 21 and 22 are supplementary angles. m2 1= 11a+19. m 2 = 6a - 9. Find m22

Answer 1

bearing in mind that supplementary angles add up to 180°.

$\bf \stackrel{\measuredangle 1}{(11a+19)}+\stackrel{\measuredangle 2}{(6a-9)}~~=~~180\implies 17a+10=180 \\\\\\ 17a=170\implies a=\cfrac{170}{17}\implies a = 10 \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\measuredangle 2}{6a-9}\implies 6(10)-9\implies 60-9\implies \stackrel{\measuredangle 2}{51}$