Question

1. Two angles of a triangle are 30% and 80°. Find the third angle.
2. One of the angles of a triangle is 80° and the other two angles are equal. Find the
measure of each of the equal angles.
3. The three angles of a triangle are in the ratio 1:2:1. Find all the angles of the triangle
Classify the triangle in two different ways.​

Answer 1

Answer:

1. Sum of all angles of triangle = 180°

Let the third angle be x degree.

30 + 80 + x = 180

110 + x = 180

x = 180 - 110

x = 70

The third angle is 70° .

2. Let one of the two equal angle measure x degree.

80 + x + x = 180

80 + 2x = 180

2x = 180 - 80

2x = 100

x = 100 / 2

x = 50 °

Thus the measure of each of the equal angles is 50 degree.