Why do angles in a triangle add to 180?

We know that angles on a straight line add to 180 degrees. Now imagine you have a triangle and the angles are called A, B and C. 

We can orientate the triangles so that we form a straight line. We can see that A, B and C lie on a straight line, so A+B+C=180. 

AK

Related Maths GCSE answers

All answers ▸

A rectangle has sides of length 4x cm and (x+3)cm and has an area less than 112 cm^2, find the set of values x can take


The point P has coordinates (3, 4) The point Q has coordinates (a, b) A line perpendicular to PQ is given by the equation 3x + 2y = 7 Find an expression for b in terms of a.


At a concert, the number of men, women and children can be expressed with the following ratio: 6:11:4 There were 6525 more women than men. How many children were at the concert?


Expand and simplify 2(a + 3) + 5(a – 1)