Formulas for Area and Perimeter

Which shapes are discussed in the video for finding the perimeter from the area?

• Equilateral triangles, squares, and circles

• Rectangles, pentagons, and hexagons

• Cubes, spheres, and cylinders

• Trapezoids, rhombuses, and ellipses

What is the formula for the area of an equilateral triangle with side length 's'?

• Area = s^2 * sqrt(2) / 4

• Area = s^2 / 2

• Area = s^2 * 3 / 4

• Area = s^2 * sqrt(3) / 4

If an equilateral triangle has an area of 1251.141 cm², what is its perimeter?

• 102 cm

• 51 cm

• 34 cm

• 68 cm

What is the formula to find the perimeter of a square from its area?

• Perimeter = 4 * sqrt(area)

• Perimeter = 2 * area

• Perimeter = area / 4

• Perimeter = 4 * area

If a square has an area of 225 square units, what is its perimeter?

• 45 units

• 30 units

• 90 units

• 60 units

What is the formula to find the circumference of a circle from its area?

• Circumference = area / pi

• Circumference = 2 * pi * sqrt(area)

• Circumference = pi * area

• Circumference = 2 * sqrt(pi * area)

If a circle has an area of 1,000 km², what is its circumference?

• 314 km

• 56 km

• 112.0714 km

• 200 km

What value of pi is used in the calculation for the circumference of a circle?

• 3.0

• 3.14159

• 3.14

• 3.2

Which of the following is NOT a step in finding the circumference of a circle from its area?

• Multiplying the area by pi

• Dividing the area by 2

• Taking the square root of the product

• Multiplying the result by 2

What is the final step in calculating the circumference of a circle from its area?

• Divide the square root by 2

• Multiply the square root by 2

• Add pi to the square root

• Subtract pi from the square root