Answer:
Hence, total surface area of the pyramid is 360 cm².
Explanation:
We first calculate slant height L of the pyramid with base s=10 cm and height 12 cm:
L²=H²+(s/2)²=122+(10/2)²=122+5²
=144+25=169⇒
L=(169)^1/2=13
The perimeter of the base is P=4s, since it is a square, therefore,
P=4×10=40 cm
The general formula for the lateral surface area of a regular pyramid is LSA=1/2Pl where P represents the perimeter of the base and l is the slant height.
Since the perimeter of the pyramid is P=40 cm and the slant height is l=13 cm, therefore, the lateral surface area is:
LSA=1/2Pl=1/2×40×13=260 cm²
Now, the area of the base B=s² with s=10 cm is:
B=s²=10²=100 cm²
The general formula for the total surface area of a regular pyramid is TSA=1/2Pl+B where P represents the perimeter of the base, l is the slant height and B is the area of the base.
Since LSA=1/2Pl=260 cm² and area of the base is B=100 cm², therefore, the total surface area is:
TSA=1/2Pl+B=260+100=360 cm²
Hence, total surface area of the pyramid is 360 cm².