 | Andrew Wheeler Phillips, Irving Fisher - 1897 - 374 pages
...angle B. §70 [Being base angles of an isosceles triangle.] , But angle »= angle A + angle B. § 58 [The exterior angle of a triangle is equal to the sum of the two opposite interior angles. Substituting A for B, n = 2A. But n is measured by arc B.£. § 185... | |
 | Andrew Wheeler Phillips, Irving Fisher - 1897 - 376 pages
...(about 600 BC). the founder of Greek mathematics and philosophy. But angle n= angle A + angle B. §58 [The exterior angle of a triangle is equal to the sum of the two opposite interior angles. Substituting A for B, n — 2A. But « is measured by arc BC. §... | |
 | James Howard Gore - 1898 - 232 pages
...angles. / A + Z £ + Z J3CM = 2 right angles. QED 80. COR. 1. Equation (a) when expressed in words is : the exterior angle of a triangle is equal to the sum of the two interior and opposite angles. 81. COR. 2. If two angles of a triangle are given, or merely their sum, the third... | |
 | F. J. Beck - 1899 - 288 pages
...of it. 5. Whaj: is a triangle? Name and define the different kinds of triangles. 6. Demonstrate: Any exterior angle of a triangle is equal to the sum of the two interior non-adjacent angles. 7. What is a quadrilateral? Name and define the three classes of quadrilaterals.... | |
 | 1899 - 658 pages
...of the angles of a. triangle meet at a point that is equi-distant from the sides of the triangle. 4. The exterior angle of a triangle is equal to the sum of the opposite interior angles. 5. Inscribe a square in a given circle. 6. Give rule for finding area... | |
 | Edward Brooks - 1901 - 278 pages
...acute angle of the other, the other acute angles are equal. TRIANGLES. PROPOSITION XVIII. — THEOREM. The exterior angle of a triangle is equal to the sum of the two opposite interior angles. Given. — Let ABC be any triangle, and CBD be its exterior angle.... | |
 | Thomas Smith (D.D.) - 1902 - 244 pages
...draw a straight line parallel to a given straight line. And so he was able in Prop. 32 to prove that the exterior angle of a triangle is equal to the sum of the two interior opposite angles. Thus it appears that Prop. 16 is only a scaffolding for the erection of Prop. 32. When the builder... | |
 | James Howard Gore - 1902 - 266 pages
...^4 + Z JB + Z BOA = 2 right angles. QED B 80. COK. 1. Equation (a) when expressed in words is : ^e exterior angle of a triangle is equal to the sum of the two interior and opposite angles. 81. COR. 2. If two angles of a triangle are given, or merely their sum, the third... | |
 | Francis Fisher Browne - 1906 - 894 pages
...charcoal diagram on the floor of his play-room, the thirty-second proposition of the first book of Euclid (the exterior angle of a triangle is equal to the sum of the two interior and opposite angles, and the three angles of a triangle together equal two right angles). In secret,... | |
 | Royal Geographical Society (Great Britain) - 1906 - 514 pages
...rays = Z_ BE 6 ; and .'. Z ab B = 2 Z pb B, and Z&BE = 2Z&BP, FIG. But and - Z &B P = Z &PB because the exterior angle of a triangle is equal to the sum of the interior and opposite angles; instrument, is divided into 10' or 20', and those are subdivided... | |
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To prove that the exterior angle of a triangle is equal to the sum of the two interior opposite angles (see fig. 
