Surface area unit test seventh grade connections Academy answers
1. What is the formula for finding the surface area of a rectangular prism?
Answer: The formula for finding the surface area of a rectangular prism is 2lw + 2lh + 2wh, where l is the length, w is the width, and h is the height.
2. Calculate the surface area of a rectangular prism with dimensions 5 cm, 3 cm, and 4 cm.
Answer: Using the formula 2lw + 2lh + 2wh, we get:
2(5)(3) + 2(5)(4) + 2(3)(4) = 30 + 40 + 24 = 94 cm²
3. What is the formula for finding the surface area of a cube?
Answer: The formula for finding the surface area of a cube is 6s², where s is the length of one side of the cube.
4. Calculate the surface area of a cube with a side length of 4 cm.
Answer: Using the formula 6s², we get:
6(4)² = 6(16) = 96 cm²
5. What is the formula for finding the surface area of a triangular prism?
Answer: The formula for finding the surface area of a triangular prism is the sum of the areas of the three faces: the two triangular bases and the three rectangular faces. The formula can be written as 2B + Ph, where B is the area of the triangular base, P is the perimeter of the base, and h is the height of the prism.
6. Calculate the surface area of a triangular prism with a triangular base with a base of 6 cm and height of 4 cm, and a height of 8 cm.
Answer: First, find the area of the triangular base:
B = 0.5bh = 0.5(6)(4) = 12 cm²
Next, find the perimeter of the triangular base:
P = a + b + c = 6 + 6 + 8 = 20 cm
Finally, using the formula 2B + Ph:
2(12) + (20)(8) = 24 + 160 = 184 cm²
7. What is the formula for finding the surface area of a cylinder?
Answer: The formula for finding the surface area of a cylinder is 2πrh + 2πr², where r is the radius and h is the height of the cylinder.
8. Calculate the surface area of a cylinder with a radius of 2 cm and a height of 5 cm.
Answer: Using the formula 2πrh + 2πr², we get:
2π(2)(5) + 2π(2)² = 20π + 8π = 28π ≈ 87.96 cm²
These are the answers to the unit test questions on surface area for seventh-grade students at Connections Academy.