Unit 8 Lesson 11: Similar Figures and surface Area

Question 1

similar

Answer 1

proportional in shape but not necessarily the same size

Question 2

surface area

Answer 2

the outside of a three-dimensional shape

Question 3

What is surface area

Answer 3

The surface area of a three-dimensional solid is the two-dimensional space occupied by the borders of the solid. You can also think of it as the outside of a three-dimensional figure; if you painted the figure, you would paint the entire surface area. In the case of spheres, the surface area is entirely curved. In the case of cylinders or cones, some of the surface area is curved, while the rest is flat. In the case of solids, such as pyramids, prisms, and cubes, the entire surface area is flat.

Question 4

First, consider the formula for the surface area of a rectangular prism:

Answer 4

A=2lh+2hw+2lw

Question 5

The formula for the surface area of a cube is

Answer 5

The formula for the surface area of a cube is 6a2
, where a
is equal to the length of one of the cube’s edges.

Question 6

The formula for the surface area of a cylinder is

Answer 6

A=2πrh+2πr2

Question 7

To determine the new surface area of a figure that has been dilated, follow the following steps.

Answer 7

• First, find the surface area of the original figure.
• Next, square the scale factor of dilation.
• Last, multiply the original surface area by the squared scale factor.

Question 8

The formula for surface area of a cone is

Answer 8

SA=πrs+πr2
.