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If a triangle has an angle of 20 degrees and another 140 what type of triangle is it?

If a triangle has an angle 25 degrees and another 65 what type of triangle and explain how u know. If a triangle has an angle of 20 degrees and another 140 what type of triangle is it and explain how you know Thanks!

Public Comments

1. 1st is right angled as the missing angle is 90 degree. 2nd is an isosceles triangle because the missing angle is another 20 degrees to make 180 degrees total inside a triangle and therefore two of the sides will be equal length.
2. ISOSCELES (Angles in a triangle add up to 180 and 140+20=160 180-160=20)
3. DUH 140 +20 +20 (180) looks isocolese (but the spelliing doesnt look right.... 3 equal angles is eqilateral 2 angles is isosolese (nope, that doesnt look right either) and theres a right angle triangle and if its got one angle, its a straight line! (all triangles add up to 180 degrees)
4. Isosceles
5. Assuming you are talking about internal angles..... All internal angles must add up to 180 degrees therefore 180-65-25=90 so the third angle is 90 deg. Bear that in mind. 180- 20-140=20 so the third angle is 20deg. also bear in mind. 3 types of triangle...... Equilateral - all sides same length and all internal angles the same. Isoscolese - 2 sides the same length and 2 internal angles the same. Scaline - all sides different lengths making all internal angles different. Therefore 20 deg 140 deg and 20 deg internal angles is isoscolese and 25 deg 65 deg and 90 deg is a scaline triangle. next time do your own homework! ;)
6. The sum of the magnitudes of interior angles of a triangle is 180 degrees. For triangle with 25 and 65 degrees, the third angle =180-(25+65) degrees =90 degrees. No two angles are equal in this triangle. So, it is scalene triangle. Also it has an angle of 90 degrees. So, it is also a right angled triangle(or right triangle). For triangle with 20 and 140 degrees, the third angle =180-(20+140) degrees =20 degrees. As this triangle has two equal angles (each of 20 degrees), it is an isosceles triangle. Also it has an angle of 140 (90<140<180) degrees,so it is an obtuse angled triangle ( or obtuse triangle).