Geometry Formulas Flashcards
What is the formula for the area of a circle?
The area of a circle is calculated using the formula A = πr², where A is the area and r is the radius.
If the radius of a circle is 3 cm, what is the area?
The area is 28.27 cm² (using A = π(3)²).
What does ‘π’ represent in the formula for the area of a circle?
π (pi) is a mathematical constant approximately equal to 3.14159.
Fill in the blank: The area of a circle is directly proportional to the square of its _____.
radius.
What is the relationship between the area and the radius of a circle?
The area increases with the square of the radius.
If the area of a circle is 50.24 cm², what is the radius?
The radius is approximately 4 cm (using r = √(A/π)).
True or False: The area of a circle can be negative.
False.
What units are used to express the area of a circle?
Square units, such as cm², m², etc.
If the diameter of a circle is 10 cm, what is its area?
The area is 78.54 cm² (using A = π(5)²).
Multiple Choice: What is the area of a circle with a radius of 0?
0 cm².
What happens to the area of a circle if the radius is doubled?
The area increases by a factor of four.
Fill in the blank: The circumference of a circle is given by the formula C = ____.
2πr.
True or False: A circle with a larger radius always has a larger area than a circle with a smaller radius.
True.
What is the area of a circle with a radius of 1 meter?
The area is approximately 3.14 m².
If the area of a circle is 78.54 cm², what is the diameter?
The diameter is approximately 10 cm.
