What is the surface area of this square based pyramid?

The surface area of the pyramid is 340.2 cm²

Step-by-step explanation:

We can find the surface area of this pyramid by adding up the area of its square base and the four side triangles.

We're told that the base has a side length of 9.0 cm, so we know that its area is (9.0cm)², or 81cm²

We are told that the height of the side triangles is 14.4 cm.  To find the area of a triangle, simply multiply its width times its height, and divide by two:

(14.4cm × 9cm) ÷ 2

= 129.6cm² ÷ 2

= 64.8 cm²

Now we can multiply that by 4, and add it to the base area to get the total surface area of the pyramid:

4 × 64.8cm² + 81cm²

= 259.2cm² + 81cm²

= 340.2cm²

c

step-by-step explanation:

1/4 and 8/3 because:

the reciprocal if 4 is 1/4 because 4 is used as 4/1 and the opposite of that is 1/4. the opposite of 3/8 is 8/3 so that is the answer.