Geometric Relationships and Circle Areas

Geometric Relationships and Circle Areas

Assessment

Interactive Video

Mathematics

9th - 10th Grade

Hard

Created by

Thomas White

FREE Resource

The video tutorial explains how to find the area of a larger circle given smaller circles with a known area. It involves setting up the problem by defining radii, connecting circle centers to form similar triangles, and using proportions to solve for the larger circle's radius. The final solution reveals that the area of the larger circle is nine times that of the smaller circles.

Read more

9 questions

Show all answers

1.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the area of each small circle?

4 units squared

1 unit squared

2 units squared

3 units squared

2.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the formula for the area of a circle in terms of its radius?

π/2r^2

2πr

πr^2

πr

3.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the goal when setting up the problem for the larger circle?

To find its radius

To find its area

To find its diameter

To find its circumference

4.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What geometric shape is formed by connecting the centers of the circles?

Square

Rectangle

Triangle

Pentagon

5.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

Why are the triangles formed by the radii and tangent lines similar?

They have equal perimeters

They are both right triangles

They have equal angles

They have equal sides

6.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the proportion set up using the similar triangles?

1/3 = Big R/(Big R + 2r)

1/4 = Big R/(Big R + 4r)

1/2 = Big R/(Big R + 3r)

1/5 = Big R/(Big R + 5r)

7.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the relationship between Big R and little r after solving the proportion?

Big R = 5r

Big R = 3r

Big R = 2r

Big R = 4r

8.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What operation is performed after finding Big R = 3r?

Subtraction

Squaring

Multiplication

Addition

9.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the final area of the larger circle?

6 units squared

7 units squared

8 units squared

9 units squared