Lesson 5.85.8 Small Group · Group 1
Group 1 · Set BSecond form · new problems, same idea
Learning target With my small group, I can find the surface area of a pyramid by adding the base area and the lateral faces — one step at a time, with support.
Remember5.8 Small Group · Group 1
To find the surface area of a square pyramid, add the base area to the area of all four triangle faces, using the slant height. The surface area of a pyramid is the base area plus the area of every triangle face.
Words: Pyramid (Pirámide)Slant height (Altura inclinada (apotema))Lateral face (Cara lateral)Base (Base)Apex (Ápice)
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1Complete each step, then write the final answer.
A square pyramid has a base that is 8 cm by 8 cm. Its slant height is 5 cm. Find its surface area.
Show your workHint Base: 8 × 8. One face: 1/2 × 8 × 5. Then add the base and 4 faces.
Final answer: -
2Complete each step, then write the final answer.
A square pyramid has a base that is 12 cm by 12 cm. Its slant height is 10 cm. Find its surface area.
Show your workHint Find the base area. Then add the 4 triangle faces.
Final answer: -
3Complete each step, then write the final answer.
A gift box is a square pyramid. Its base is 7 in by 7 in. Its slant height is 9 in. How much paper covers every face?
Show your workHint Every face means the square base and the 4 triangle faces.
Final answer: -
4Complete each step, then write the final answer.
A pyramid has a rectangle base, 16 cm by 9 cm. The two triangles on the 16 cm edges have a slant height of 7.5 cm. The two on the 9 cm edges have a slant height of 10 cm. Find the surface area.
Show your workHint There are two sizes of triangle faces. Find each size and use it twice.
Final answer:
Explain your thinkingWhy do we use the slant height for the triangle faces? Why must we add the base too?
Sentence starter We use the slant height because ___. · We add the base because ___.