Tham khảo tài liệu 'review of math topics for the sat phần 3', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 2 Similar Triangles Similar triangles have the same shape corresponding angles are equal and corresponding sides are proportional. 3 Area of a Triangle Area of Triangle 1 2 Base Height The height is the perpendicular distance between the side that is chosen as the base and the opposite vertex. Example If a triangle of base 6 has the same area as a circle of radius 6 what is the altitude of the triangle Solution The area of the circle is 6 6 36. In the triangle 1 2 6 Height 36 pi solving for Height Height 12 pi 4 Triangle Inequality Theorem The length of one side of a triangle must be greater than the difference and less than the sum of the lengths of the other two sides. Example if it is given that the length of one side is 3 and the length of another side is 7 then you know that the length of the third side must be greater than 7 -3 4 and less than 7 3 10. 5 Isosceles Triangles An isosceles triangle is a triangle that has two equal sides. Not only are two sides equal but the angles opposite the equal sides called base angles are also equal. Example The vertex angle of an isosceles triangle is p degrees. How many degrees are there in one of the base angles Solution There are 180 - p degrees left which must be divided by two congruent angles. Each angle will contain 180 - p 2 or 90 - p 2 degrees. 6 Equilateral Triangles In equilateral triangles all three sides and all three angles are equal. All three angles in an equilateral triangle measure 60 degrees regardless of the lengths of sides. Q. RIGHT TRIANGLES By definition a right triangle contains a 90 degree angle. 1 Pythagorean Theorem For all right triangles 2 leg leg 2 2 hypotenuse In this case 2 2 3 3 4 9 13. Thus the hypotenuse is the square root of 13. Example A strobe light is 5 feet from one wall of a room and 10 feet from the wall at right angles to it. How many feet is it from the intersection of the two walls Solution The situation is describing a right triangle in which the hypotenuse is the unknown .
