To find conjecture about regular polygon, use the formula

Where, n = number of sides of the regular polygone
1) Triangle
n =3
So, Conjecture of the triangle =

= 120
2) Square
n =4
So, Conjecture of the square =

= 90
3) Pentagone
n = 5
So, Conjecture of the pentagon =

= 72
4) Hexagone
n = 6
So, Conjecture of the pentagon =

= 60.
Answer:
55 inches
Step-by-step explanation:
2 posters x 28 inches each = 56
221 - 56 = 165 inches
3 blank spaces on wall
165 ÷ 3 = 55 inches between posters and on either side
Answer:
<1 = 48
Step-by-step explanation:
<1 + <2 + <3 = 180 since they form a line
<1 + 90+ 42 =180
Combine like terms
<1 + 132 =180
Subtract 132 from each side
<1 +132-132 =180-132
<1 = 48