Question

The sum of the measures of angles for a triangle is 180°. Find the value of x and then the measures of the 3 angles

Answer 1

Answer:

The value of x is 50

The measures of the 3 angles are 50°, 100°, 30°

Step-by-step explanation:

Let us solve the question

∵ The sum of the measures of the angles of a triangle is 180°

∵ The measures of the 3 angles of the given Δ are x°, 2x°, (x - 20)°

→ Add them and equate the sum by 180

∴ x° + 2x° + (x - 20)° = 180°

→ Add the like terms

∵ (x + 2x + x) + (-20) = 180

∴ 4x - 20 = 180

→ Add 20 to both sides

∵ 4x - 20 + 20 = 180 + 20

∴ 4x = 200

→ Divide both sides by 4 to find x

∴ x = 50

∴ The value of x is 50

To find the measures of the 3 angles substitute x by 50 in their expressions

∵ The measure of one angle is x

∴ The measure of the 1st angle is 50°

∵ The measure of the 2nd angle is 2x

∴ The measure of the 2nd angle = 2(50)

∴ The measure of the 2nd angle is 100°

∵ The measure of the 3rd angle is (x - 20)

∴ The measure of the 3rd angle = (50 - 20)

∴ The measure of the 3rd angle is 30°

∴ The measures of the 3 angles are 50°, 100°, 30°