Symmetry in Circles Isosceles triangles have two equal sides and two equal angles. e° f° b° 30° n° e = (180 – 30)°  2 m° a° 70° = 75° 110° a = 70°

Slides:

Advertisements

Similar presentations

Triangles TOPIC 9 LESSON 9-5.

Advertisements

S3 BLOCK 8 Angles and Circles I can find the size of a missing angle using the following facts. Angle in a semi circle. Two radii and a chord form an isosceles.

Chapter 5 Perpendicular Bisectors. Perpendicular bisector A segment, ray or line that is perpendicular to a segment at its midpoint.

Regular Polygons A polygon is regular if all sides and interior angles are congruent. Congruent: same size, same shape.

We can work this out without a calculator.

Isosceles and Equilateral Triangles Section 5-1. Isosceles Triangle A triangle with at least two congruent sides. Leg Leg Base Vertex Angle Base Angles.

Warm-up. Legs: Congruent sides Of an isosceles triangle Base: Third side of an Isosceles triangle Vertex Angle: the angle the two legs form Base Angle:

11/18/09 Do Now Have your homework out on your desk. Find all of the angle measures below.

Ch. 3 Review Part II Honors Geometry. Ch. 3 Test (Part II) Review  Median: Divides side to which it is drawn into two congruent segments.  Altitude:

A chord of a circle is subtended by an angle of x degrees. The radius of the circle is 6 √ 2. What is the length of the minor arc subtended by the chord?

The angles add up to 2 X 180 = 360º D B A + B + C + D =360

Symmetry in Circles (II) Chords A chord is a line connecting any two points on the circumference. chord The biggest possible chord is thediameter.

Special Right Triangles. Draw 5 squares with each side length increasing by

Lesson Handout #1-7 (ODD), (ODD) ** For each question:  BOX the exact value  CIRCLE the approximate value (.01)

Shapes and their properties. What am I? I have 2 pairs of equal sides I have 2 pairs of parallel sides I have 0 lines of symmetry I have no right-angles.

Triangle A polygon with three sides and three angles. A triangle can be names by its’ side lengths and angles. – Side lengths: isosceles, equilateral,

Do Now: For isosceles triangle, find the indicated measure. Isosceles Triangles Do Now & Notes Name:______________________ Date:______________ Group:_______.

1 An isosceles triangle has one line of symmetry.

Right Triangles Consider the following right triangle.

©G Dear2008 – Not to be sold/Free to use

TRIANGLES AND TYPES OF TRIANGLES. A triangle has three sides.

Types of Triangles. Equilateral Triangle All sides are the same length and all the angles are the same length.

Triangles 1st year P26 Chapter 4.

The distance from any point on a circle to the center is a constant called the radius. The length of any line segment from a point on a circle to the.

Triangles Shapes with 3 sides! Equilateral Triangle All 3 Sides are equal in Length All 3 interior angles are the same.

D B A C 3.2—Isosceles and Equilateral Triangles. Objective: Use properties of _______________, and ________________triangles. equilateral Vocabulary:

Triangle Congruence 4.5 Isosceles and Equilateral Triangles.

Time for Triangles. What is a triangle? A triangle is a polygon. It has 3 sides and 3 angles. It can also be called a trigon.

Isosceles Triangles Theorems Theorem 8.12 – If two sides of a triangle are equal in measure, then the angles opposite those sides are equal in measure.

Classifying Triangles How many degrees can be found in all triangles? 180 We can classify triangles 2 ways: By their angles By their sides.

Scalene triangle: A scalene triangle is a triangle that has no equal sides. The following is a scalene triangle.

CIRCLE THEOREMS LO: To understand the angle theorems created with a circle and how to use them. Draw and label the following parts of the circle shown.

Angles In Triangles Types of Triangles Isosceles triangle

All about Triangles Ask Boffin!.

Example Draw and reflect an isosceles triangle

Example Draw and reflect an isosceles triangle

Classifying Triangles

Isosceles Triangles.

Imagine a triangle made by connecting the dots on the circumference or in the centre of the circle. Without pointing, how can you describe your triangle?

Classifying Triangles

Angles In Triangles Types of Triangles Isosceles triangle

8.4 Areas of Regular Polygons

Triangles Created by G. Antidormi 2005.

Angles In Triangles Types of Triangles Isosceles triangle

Areas of Regular Polygons

Classifying Triangles

Inside angles theorem.

So the large triangle is right-angled.

Objective - To classify triangles.

Identify type of triangle

Types of Triangles Thursday, 11 April 2019.

Types of Triangles Thursday, 11 April 2019.

SHAPES By: Ms. Conquest.

Isosceles Triangles. Isosceles Triangles Base Angles If 2 angles in a triangle are congruent, then the sides opposite them are congruent.

Isosceles Triangles. Isosceles Triangles Base Angles If 2 angles in a triangle are congruent, then the sides opposite them are congruent.

3-3 Parallel Lines & the Triangle Angle Sum Theorem

4-1 Vocabulary Acute triangle Equiangular triangle Right triangle

Front of Flipbook Right Triangles Acute Triangles Obtuse Triangles

Unit 9. Day 17..

Circle Theorem Proofs Semi-Circle Centre Cyclic Quadrilateral

8.4 Areas of Regular Polygons

Equilateral TRIANGLES

Circle Theorems Give a REASON for each answer

Lesson 3-2 Isosceles Triangles.

Presentation transcript:

Symmetry in Circles Isosceles triangles have two equal sides and two equal angles. e° f° b° 30° n° e = (180 – 30)°  2 m° a° 70° = 75° 110° a = 70° f = e = 75° b = 180 – 70 – 70 = 40° m = 180 –110 = 70° n = 180 – 70 - 70 = 40°

Isosceles Triangles & Circles If we draw a triangle inside a circle using radii then it will be isosceles because it has two equal sides. Ex1 Ex2 v° w° c° b° a° 12° f° e° a = 12° e° = f° b = 180 – 12 – 12 = 156° v° = w° c = 180 – 156 = 24°

Ex3 p = 65° t° q = 180 – 65 – 65 = 50° 120° r° r = 360 – 120 – 50 = 190° q° s° p° s = (180 – 120)  2 = 30° 65° t = s = 30°

So the large triangle is right-angled. Ex4 a = (180 – 40)  2 = 70° b = a = 70° e° c° 40° c = 180 – 40 = 140° a° d° b° d = (180 – 140)  2 = 20° e = d = 20° NB: b + d = 70 + 20 = 90° So the large triangle is right-angled.