Perimeter of circle formula:
2πr or πd
What do you do when it says on your pi question, “… to 2 decimal places”?
press π button on calculator
What do you do when it says “exact circumference”?
Keep π in your answer
What do you do if you have to find the perimeter of the arc length?
θ/360 x πd
How do you find the exact perimeter?
You find the arc length first then substitute it into the perimeter formula and times the radius by 2.
What is the area of a circle?
πr²
What is the area of a sector?
θ/360 x πr²