# Surface area of Triangular Prisms and Cylinders

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This pdf discusses finding the surface area of triangular prisms and cylinders step by step to get through the basics with examples.
1. 18. Tuesday 16th June: Surface area of triangular
prisms and cylinders
8X1 – Summer Term 2
Today’s lesson is about calculating the surface area of rectilinear shapes. I have
split the lesson into two parts:
 Part 1: Surface area of triangular prisms
 Part 2: Surface area of cylinders
 Homework: 1 task on mathswatch
Answers are at the end of the document.
Part 1 – Surface area of triangular prisms
Surface area of a triangular prism:
EG 1: Find the surface area of a triangular prism
2. Find the surface area of each of the following trianglular prisms
3. Part 2 – Surface area of cylinders
Two videos to watch to help understanding:
Surface area of cylinders:
EG 2: Find the surface area of the cylinder
Surface Area
Area of top: 𝝅 × 𝟑𝟐 = 𝟗𝝅
Area of base: 𝟗𝝅
Area of curved surface area: circumference of
the circle × height: 𝟔 × 𝝅 × 𝟏𝟎 = 𝟔𝟎𝝅
Total = 𝟔𝟎𝝅 + 𝟗 𝝅 + 𝟗𝝅 = 𝟕𝟖𝝅
EG 3: Working backwards, given the surface area
𝜋 × 32 + 𝜋 × 32 + (2 × 3 × 𝜋 × ℎ) = 84𝜋
18𝜋 + 6𝜋ℎ = 84𝜋
6𝜋ℎ = 66𝜋
6ℎ = 66
ℎ = 11
4. Question 1 Question 2
Calculate the surface area to 2dp Calculate the surface area to 2dp
Question 3 Question 4
Calculate the surface area to 2dp Calculate the surface area in terms of 𝜋
Question 5 Question 6
Calculate the surface area in terms of 𝜋 Calculate the height
Question 7 Question 8
Calculate the height Calculate the height to 2 dp
Now complete the mathswatch 
1) 330cm²
2) 456cm²
3) 528cm²
4) 84cm²
5) 240cm²
6) 660cm²
Part 2
1) 1011.59cm²
2) 653.45cm²
3) 32.99m²
4) 28𝛑 cm²
5) 72𝛑 cm²
6) 35cm
7) 3cm
8) 1.3cm (1.30cm)