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Triangles, Perimeter and Area, Problem Solving.pptx
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- 2. Triangle A triangle isa simple polygon with 3 sides and 3 interior angles. It is one of the basic shapes in geometry in which the 3 vertices are joined with each other and it is denoted by the symbol . △ P Q R base (b) height (h)
- 3. Triangle P Q R △PQR 3 Vertices Point P PointQ Point R 3 Angles P Q R 3 Sides PQ QR PR
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- 6. Scalene triangle P Q R Scalene triangle isa triangle that has no equal sides.
- 7. Isosceles triangle P Q R Isosceles triangle isa triangle that has two equal sides.
- 8. equilateral triangle P Q R Equilateral triangle isa triangle that has three equal sides.
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- 10. acute triangle P Q R Acute triangleis a triangle that has three acute angles. Note: An acute angle is an angle measures greater than 0° but less than 90° 50° 60° 70°
- 11. right triangle P Q R Right triangleis a triangle that has one right angle. Note: An right angle is an angle measures exactly 90° 30° 60° Indicates that the measurement of the angle is 90°
- 12. equiangular triangle P Q R Equiangular triangle isa triangle with all angles are equal. Note: All angles of an equiangular triangle measure 60° 60° 60° 60°
- 13. Perimete r of a triangle P Q R Aperimeter of a triangle is defined as the total length of the outer boundary of the triangle. Or we can say, the perimeter of the triangle is equal to the sum of all its three sides. The unit of the perimeter is same as the unit of sides of the triangle.
- 14. Perimete r of a triangle P Q R IfPQR is a triangle, where , and are the lengths of its sides, then the perimeter of PQR is given △ by: Perimeter = +
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- 16. Example Number 1 Perimeter= + A B C 10 cm 9 cm 7 cm Solution: Perimeter = + Perimeter = Therefore, the perimeter of ABC is 26 cm. △
- 17. Example Number 2 Perimeterof the triangular roof = side 1 + side 2 + side 3 A roofing company is designing a triangular roof for a new shed. The three sides of the roof are 5 meters, 6 meters, and 8 meters long. If the company needs to install roofing materials along the perimeter, how many meters of material will they need? Perimeter of the triangular roof = 5 m + 6 m + 8 m Perimeter of the triangular roof = 19 m Therefore, the company needs 19 m of install roofing materials. Solution:
- 18. Exercise number1 A B C 22 cm14 cm 10 cm
- 19. Exercise Number 2 Atriangular park bench has sides that are 4 feet, 6 feet, and 8 feet long. If a park maintenance worker needs to replace the perimeter of the bench with new wood slats, how many feet of wood will he need to cut?
- 20. Area of a triangle Thearea of a triangle is the region occupied by the triangle in 2D space. The area for different triangles varies from each other depending on their dimensions. We can calculate the area if we know the base length and the height of a triangle. It is measured in square units. P Q R base (b) height (h)
- 21. Area of a triangle Areaof triangle = Half of Product of Base and Height P Q R base (b) height (h) S Area of triangle =
- 22. Solving area of atriangle
- 23. Example Number 1 Area= A B C 10 cm 8 cm Solution: Area = Area = Therefore, the area of ABC △ is 40 . Area =
- 24. Example Number 2 Areaof triangular flag = A school is creating a triangular flag for a special event. The base of the flag is 12 inches, and the height is 10 inches. How much fabric will the school need to make the flag? Therefore, the school needs of fabric. Solution: Area of triangular flag = Area of triangular flag = Area of triangular flag =
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- 26. Exercise Number 2 Atriangular section of a playground has a base of 20 meters and a height of 12 meters. The city is planning to install rubber flooring over this area. How many square meters of flooring will they need?