Brilliant

Home Courses Today

Excel in math and science.

Join using Facebook Join using Google Join using email

Forgot password? New user? Sign up

Existing user? Log in

Your answer seems reasonable. Find out if you're right!

That seems reasonable. Find out if you're right!

Join using Facebook Join using Google Join using email

Forgot password? New user? Sign up

Existing user? Log in

Geometry

Properties of Circles

Concept Quizzes

Properties of Circles Warmup
Circles - Radius and Diameter and Circumference
Circles - Area
Circles - Central Angles
Circles - Inscribed Angles
Circles - Arc Length
Circles - Sector Area
Circles Problem Solving

Challenge Quizzes

Circle Properties: Level 1 Challenges
Circle Properties: Level 2 Challenges
Circle Properties: Level 3 Challenges

Circles Problem Solving

In the above diagram, $d_1=24$ and $d_2=18.$ What is the perimeter of the green colored region?

{84}\pi

{78}\pi

{48}\pi

{42}\pi

Show explanation

View wiki

by Brilliant Staff

In the above image of a circle with center at $O,$ $\angle ABC = 115 ^ \circ$ . What is angle $AOC$ (as marked) equal to?

130 ^ \circ

65 ^ \circ

230 ^ \circ

115 ^ \circ

Show explanation

View wiki

by Brilliant Staff

The length of each side in the above square is $14.$ If the two curves in the square are each one quarter of a circle with radius $14,$ calculate the area of the region bounded by the two curves in the above diagram.

98\pi - 196

392\pi - 196

14\pi - 392

196\pi - 98

Show explanation

View wiki

by Brilliant Staff

$\Gamma$ is a circle with center $O$ . $A$ and $B$ are points on $\Gamma$ such that the sector $AOB$ has perimeter $80$ . What is the maximal possible area of sector $AOB$ ?

Show explanation

View wiki

by Brilliant Staff

Let $O_1$ and $O_2$ be the centers of two circles with the same radius $15\text{ cm}.$ What is the perimeter of the green colored region?

{15}\pi \text{ cm}

{5}\pi \text{ cm}

{20}\pi \text{ cm}

{30}\pi \text{ cm}

Show explanation

View wiki

by Brilliant Staff

Problem Loading...

Note Loading...

Set Loading...