Question

PLZ I NEED HELP NOW THANKS

Answer 1

Answer:

1240.4 mm²

Step-by-step explanation:

SA of Pentagonal pyramid:

(as)(5/2) + (sl)(5/2)

↑ ↑

base area lateral area

_____________________

a: apothem (in-radius) length, s: side length.

l: slant height.

______________________

Since we are already given the base area which is 440.4 mm². All we need to do is find the lateral area and add both areas together.

Given that the triangular face of the lateral part has a side/base length of 16mm, and a 20mm slant height.

A triangle has an area of ½bh and since there are 5 of these faces total, (5)(½bh) = (5/2)(bh). In a three dimensional perspective, b will be s and h will be l so (sl)(5/2).

With this information the surface area is:

(16)(20)(5/2)mm + (440.4 mm²) →

800 mm² + 440.4 mm² =

1240.4 mm²