Answer:
Step-by-step explanation:
Total surface area:
- A = 4(1/2*7*l) + 7² = 14l + 49, where l is a slant height
We are given:
Find the value of l:
- 14l + 49 = 161
- 14l = 112
- l = 112/14
- l = 8 cm
Use Pythagorean to find the height h of the pyramid:
- l² = h² + (7/2)²
- 8² = h² + 3.5²
- h² = 8² - 3.5²
- h² = 51.75
- h = √51.75
- h ≈ 7.2 cm
Find the volume:
- V = 1/3Bh
- V = 1/3*7²*7.2
- V = 117.6 cm³
