So if Caelyn collected 21 shells in total and her brother collected 4 times as much all you need to do is multiply 21 by 4 and you get your answer which is 84
7 plus 6 is 13 plus 8 is 21 now if you add 21 more it will be 42. or you could multiply 21 times 2 which would also be 42 in that case 42 in your answer.
The interior angles next to the 2h angles are congruent and each one measures 70 degrees. Since the interior angle is 70 degrees the exterior angle is 110 degrees. 2h = 110 divide both sides by 2 h = 55
