Question

The sum of the two angles of a triangle is 80 degree and their difference is 20 degree. find all the angles of the triangle.

Answer 1

The sum of the interior angles in a triangle is 180.

We can find what one of angles are. Since the sum of two angles are 80, that leaves the third angle.

180-80=100

This means one angle equals 100.

We can make an equation to find what the two angles are. Let's have x as the smaller angle.

x+x+20=80; since their difference is 20.

2x+20=80; let's subtact 20.

2x=60; now divide by 2.

x=30

Since the smaller angle of the two is 30, the other is 50.

So, the angles of the triangle are 30°, 50°, and 100°

Answer 2

Sum of 2 angles = 80°

Difference = 20°

If we take away 20° from the sum, both angles are equal

⇒80 - 20 = 60°

Divide by 2 to find the smaller angle:

60 ÷ 2 = 30

Add 20° to find the bigger angle:

20 + 30 = 50°

One of the angle is 30° and the other angle is 50°

Given that the sum of the two angles is 80°

⇒ Third angle = 180 - 80 = 100°

Answer: The 3 angles are 30° , 50° and 100°