5.8 · Part II
Second Practice Form · Independent Application and Spiral Review
Surface Area of Pyramids · Pyramid
- Calculate area of base polygon (square, rectangle, or triangle)
- Calculate area of each triangular face using ½ × base × slant height
- Add the base area and all triangular face areas together
- Surface Area of Pyramids (Área de superficie de pirámides) — The total area of a pyramid's base and triangular faces. Formula: SA = B + lateral area.
- Pyramid (Pirámide) — A solid with a flat bottom and triangle sides that meet at one point on top.
- Slant height (Altura inclinada (apotema)) — The height of a side triangle, measured along its slanted face.
- Lateral face (Cara lateral) — A triangle side of a pyramid, not the bottom.
- Base (Base) — The flat bottom of a pyramid.
- Apex (Ápice) — The point at the top of a pyramid where the sides meet.
- A common mistake in Surface Area of Pyramids is finding the four triangular lateral faces correctly (½ × base edge × slant height, times 4) and then stopping — forgetting to add the base area at the end. This leaves the total surface area too small by exactly the base's area. Before you submit, ask: 'Did I add the base area to the four lateral faces, or did I stop after the sides?'
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1 MULTIPLE CHOICE
A gift box is a square pyramid with a base edge of 9 in. What is the area of its square base (the part that sits on the table)?
- A81 in²
- B36 in²
- C18 in²
- D324 in²
FormulaPut the numbers inWork it outAnswer with its unit -
2 MULTIPLE CHOICE
A square pyramid has a base edge of 5 in and a slant height of 7 in. What is the surface area?
- A95 in²
- B70 in²
- C95 in³
- D120 in²
FormulaPut the numbers inWork it outAnswer with its unit -
3 MULTIPLE CHOICE
How many lateral (triangular) faces does a square pyramid have?
- A4
- B3
- C5
- D6
✏️ Workspace & Solution Steps -
4 MULTIPLE CHOICE
What is the area of one triangular face with base 8 in and slant height 6 in?
- A24 in²
- B48 in²
- C14 in²
- D24 in³
FormulaPut the numbers inWork it outAnswer with its unit
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5 OPEN RESPONSE
Two pyramids have the same base area (64 in²) but different slant heights. Pyramid A has slant height 6 in and Pyramid B has slant height 10 in. How much more surface area does Pyramid B have? Why does slant height affect surface area but NOT base area?
✏️ Mathematical Justification & Response
Writing Task: Justify why your mathematical solution is accurate and complete.