Surface Area Examples
This cube has six congruent faces, each with a length and width of 3 cm.
Area of one face = 3 x 3 cm = 9 cm2
Surface area = 6 sides x 9 cm2 = 54 cm2
This trapezoidal prism has six sides, two congruent trapezoids and four rectangles.
This cylinder has two circles (each with a radius of 2 cm) and one rectangle (with a length of 5.8 cm and a width the circumference of the circles).
This pyramid is made up of four equilateral triangles.
Here we just need to find the area of one triangle and multiply it by four sides:
Area of 1 triangle = ½bh = ½(8 x 6.9) = 27.6 cm2
Now, multiply that by four sides, and we're done.
The diameter of this sphere is 11.9 cm, so the radius is half of that, 5.95 cm.
The area of the circular base is equal to: