3420°
explanation:
the equation of the sum of interior angles are (n-2)x180
polygon above has 21 sides so you sub n as 21 and plug the equation in the calculator
Answer:
x=−2
Step-by-step explanation: Step 1: Simplify both sides of the equation.
3(x−5)−3=5(x−2)+2x
(3)(x)+(3)(−5)+−3=(5)(x)+(5)(−2)+2x(Distribute)
3x+−15+−3=5x+−10+2x
(3x)+(−15+−3)=(5x+2x)+(−10)(Combine Like Terms)
3x+−18=7x+−10
3x−18=7x−10
Step 2: Subtract 7x from both sides.
3x−18−7x=7x−10−7x
−4x−18=−10
Step 3: Add 18 to both sides.
−4x−18+18=−10+18
−4x=8
Step 4: Divide both sides by -4.
−4x
−4
=
8
−4
x=−2
Answer:(-1, 5)
Step-by-step explanation:
Add X1 + X2 then divide by 2. Add Y1 + Y2 then divide by 2.
