Question

Find the measure of the third angle of the triangle whose two angles are 100° and 20°.​

Answer 1

Answer:

60°

Step-by-step explanation:

According to the angle sum property of triangle, the sum of all three angles of a triangle is 180°.

Given, two angles = 100° and 20°

=> Third angle = 180° - (100 + 20)° = 180° - 120° = 60°

Answer 2

Question:

• Find the measure of the third angle of the triangle whose two angles are 100° and 20°.

Given:

• the measures of 2 angles in a triangle are 100° and 20°

To Find:

• the measure of third angle.

Solution:

we know that, to find the measures of unknown angles in a triangle we use angle sum or which states that sum of interior angles in a triangle are equivalent to 180°

now, let the third angle be y

$: \implies \sf \: 100 \degree + 20 \degree + \blue { y \degree} = 180 \degree \\ \\ \\ : \implies \sf120 \degree + \blue{ y \degree} = 180 \degree \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \\ : \implies \sf \blue{y \degree} = 180 \degree - 120 \degree \: \: \: \: \: \: \: \: \: \: \: \\ \\ \\ : \implies \sf \blue{y \degree} = 60 \degree \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$

hence the third angle equals 60°

Do you know.?

• A triangle has three sides, three angles, and three vertices.

• The sum of the length of any two sides of a triangle is greater than the length of the third side.

• Any exterior angle of the triangle is equal to the sum of its interior opposite angles. This is called the exterior angle property of a triangle.

hope this helps:)