Please help with these 3

3) 146 degrees

4) 471 degrees

5) x = 100 and 3x = 300

Step-by-step explanation:

all three are polygons whose sum of all interior angles can be found by using the formula (n - 2)*180 where 'n' refers to the number of sides

In #3 and 5 there are 5 sides, so (5 - 2)*180 = 3(180) giving a total of 540 degrees. Add all known angles and deduct from 540.

#4 has 7 sides, so (7 - 2)*180 = 1260 degrees. Add all known angles and deduct sum from 1260.

#5 Add all integers plus 'x' + '2x' to get 240 + 3x = 540

160 sq. uits

Step-by-step explanation:

160 sq. uits é a resposta