## Part 1: Understanding the Basics of Circles

Hello from MKSprep, the trusted SAT preparation center in Putalisadak, Kathmandu, Nepal. We are now ready to take a circular journey in our SAT math series! This first part of our in-depth exploration into Circles will set the foundation for understanding this key geometric shape.

### Introduction to Circles

In mathematics, a circle is a shape consisting of all points in a plane at a given distance from a certain point, known as the circle’s center. The radius is the distance between any point on the circle and its center.

### Diameter, Circumference, and Area

Here are some fundamental concepts related to circles:

• Diameter: The longest line can be drawn in a circle, passing through the center. The diameter is twice the radius of the circle.
• Circumference: The circumference is the boundary or the distance around the circle. For any circle, the circumference is more than three times the diameter. This relationship is expressed by the formula C = πd or C = 2πr.
• Area: The area of a circle is the number of square units that can fit inside it. It is calculated as A = πr².

Understanding these basic concepts is crucial for solving circle-related problems in the SAT math section.

Stay tuned for the next part, where we delve into arcs and sectors. At MKSprep, we are committed to making your SAT preparation as smooth as possible!

## Part 2: Arcs and Sectors in Circles

Welcome back to the SAT preparation series by MKSprep, your trusted SAT preparation center in Putalisadak, Kathmandu, Nepal. In this second part on Circles, we dive deeper into two integral components – Arcs and Sectors.

### Arcs in Circles

An arc in a circle is a portion of the circumference. The length of an arc is proportional to the degree measure of its central angle. In other words, if you have a 60° angle at the center of the circle, the length of the arc will be 1/6 of the total circumference. This relationship is expressed as Arc length = (θ/360°) × 2πr, where θ is the degree measure of the central angle.

### Sectors in Circles

A sector of a circle is the region enclosed by two radii and their intercepted arc. It resembles a slice of pie. Similar to arcs, the area of a sector is proportional to the degree measure of its central angle. Therefore, if a circle is divided into a sector by a 60° angle, the area of the sector will be 1/6 of the total area of the circle. This relationship is expressed as Sector area = (θ/360°) × πr², where θ is the degree measure of the central angle.

Understanding these concepts will help you efficiently tackle SAT math questions related to arcs and sectors.

Stay tuned for our next lesson, where we will explore the properties of chords in circles. At MKSprep, we are committed to equipping you with the knowledge and skills needed for SAT success!

## Part 3: Chords in Circles

Greetings once more from MKSprep, your preferred SAT preparation center located in Putalisadak, Kathmandu, Nepal. Continuing with our deep dive into Circles, in this third part, we will discuss an essential concept: Chords.

### What is a Chord?

In the context of a circle, a chord is a straight-line segment connecting two circumference points. The longest possible chord of a circle runs through the circle’s center and is known as the diameter.

### Properties of Chords

Here are some key properties of chords:

• Equal Chords: In the same or in congruent circles, two minor arcs are congruent if their corresponding chords are congruent.
• Perpendicular to the Chord: A radius or diameter perpendicular to a chord bisects the chord (divides it into two equal parts) and the arc it subtends (the arc that it cuts off).
• Chords Equidistant from the Center: In the same circle or congruent circles, two chords are equidistant from the center if and only if congruent.

Comprehending these properties is crucial for solving SAT math questions that involve chords in circles.

In our next installment, we will examine the concept of tangents to a circle. At MKSprep, we are dedicated to ensuring your SAT preparation is thorough and fruitful!

## Part 4: Tangents to Circles

Welcome back to our SAT preparation series provided by MKSprep, your leading SAT preparation center in Putalisadak, Kathmandu, Nepal. In this fourth part of our deep dive into Circles, we’re going to explore the fascinating world of tangents.

### What is a Tangent?

A tangent to a circle is a straight line that touches the circle at exactly one point, known as the point of tangency. An important property to remember is that a radius drawn to the point of tangency is always perpendicular to the tangent line.

### Properties of Tangents

Here are some significant properties of tangents to remember:

• Tangent Segments from a Point: From a point outside a circle, the two tangent segments to the circle are congruent. This means they have the same length.
• Angles between Tangents and Radii: The angle between the radius of a circle and a tangent line drawn to that circle from the endpoint of the radius is always a right angle (90 degrees).
• Angles formed by Tangents: The angle formed by two tangents, two secants, or a secant and a tangent drawn from a point outside the circle is half the difference of the measures of the intercepted arcs.

Understanding these properties will significantly assist you in successfully navigating SAT math questions involving tangents to circles.

Join us for the next lesson, where we’ll delve into the intriguing topic of inscribed angles in circles. At MKSprep, we’re committed to providing you with the most effective SAT preparation possible!

## Part 5: Inscribed Angles in Circles

Hello again from MKSprep, your SAT preparation center situated in the heart of Putalisadak, Kathmandu, Nepal. As we continue our exploration of Circles, this fifth part introduces a key concept: Inscribed Angles.

### What is an Inscribed Angle?

An inscribed angle is formed by two chords in a circle with a common endpoint. This common endpoint forms the vertex of the inscribed angle. The other two endpoints define what is known as an intercepted arc on the circle’s circumference.

### Properties of Inscribed Angles

Here are the essential properties of inscribed angles:

• Measure of an Inscribed Angle: The measure of an inscribed angle is half the measure of its intercepted arc.
• Inscribed Angles on the Same Arc: All inscribed angles that intercept the same arc are equal.
• Inscribed Angle and a Diameter: An inscribed angle that intercepts a semicircle (where the arc is a diameter) is always a right angle (90 degrees).

Grasping these properties will greatly assist you in solving SAT math problems involving inscribed angles in circles.

Stay tuned for our next section, where we will dive into sector and arc length in circles. At MKSprep, we ensure that your SAT preparation journey is comprehensive and rewarding!

## Part 6: Sectors and Arc Lengths in Circles

Welcome once again to our SAT preparation series offered by MKSprep, your trustworthy SAT preparation center in Putalisadak, Kathmandu, Nepal. We’re discussing sectors and arc lengths in this sixth part of our circle exploration.

### What are Sectors and Arc Lengths?

A sector of a circle is a section of the circle enclosed by two radii and their intercepted arc. The length of an arc is simply the distance along the path of the circle from one point to another.

### How to Find Sectors and Arc Lengths?

Here’s how you calculate these two key components:

• Sector Area: To find the area of a sector, you need to know the measure of the central angle that subtends it. The formula for the sector area is (main angle/360) * π * r², where r is the circle’s radius.
• Arc Length: The arc length is found using a formula similar to the sector area’s. The formula is (central angle/360) * 2πr, again where r is the circle’s radius.

Understanding these principles will be incredibly beneficial in tackling SAT math questions concerning sectors and arc lengths in circles.

Join us in the next segment, where we’ll investigate the compelling topic of chords in circles. MKSprep is dedicated to providing you with the highest standard of SAT preparation!

## Part 7: Chords in Circles

Welcome back to MKSprep, your dedicated SAT preparation center in Putalisadak, Kathmandu, Nepal. In this seventh part of our circle series, we are focusing on the concept of chords.

### What are Chords?

A chord is a straight-line segment that connects two points on the circumference of a circle. The longest possible chord in a circle is its diameter.

### Significant Properties of Chords:

Let’s explore some of the important properties of chords:

• Equal Chords: Equal chords of a circle subtend equal angles at the circle’s center. Conversely, if the angles subtended by two chords at the center of the circle are equal, the chords are also equal.
• Perpendicular from the Center: If a perpendicular is drawn from the center of the circle to a chord, it bisects the chord. That means it divides the chord into two equal parts.
• Chords Equidistant from Center: Chords that are equidistant from the center of the circle are equal in length.

Knowing these chord properties can greatly assist you in answering SAT math questions related to chords in circles.

Join us in our final installment of this series, where we’ll be dealing with tangents and their properties. MKSprep is committed to making your SAT preparation journey as comprehensive as possible!

## Part 8: Tangents to Circles

Congratulations on reaching the final part of our SAT preparation series on circles offered by MKSprep, your reliable SAT preparation center in Putalisadak, Kathmandu, Nepal. In this concluding segment, we’re studying the concept of tangents to circles.

### What is a Tangent?

A tangent is a line that touches a circle at exactly one point, known as the point of tangency. No matter where the tangent line touches the circle, it is always perpendicular to the radius drawn to the point of tangency.

### Key Properties of Tangents:

Below are some significant properties of tangents:

• Tangent Segment: A tangent segment is a line segment whose endpoints are the point of tangency and a point on the tangent line.
• Tangent Segments from an External Point: Those segments are congruent if two tangent segments are drawn to a circle from an external point.

Understanding these properties will be immensely helpful in answering SAT math questions related to tangents to circles.

With the conclusion of this part, we’ve covered all the fundamental elements of circles that you’ll encounter in the SAT. Thank you for choosing MKSprep as your companion in your SAT preparation journey!