Question

In the figure shown, what is the measure of angle x?

Triangle ABC has measure of angle BAC equal to 40 degrees and the measure of angle ABC is equal to 70 degrees. The side BC of the triangle is extended till D. The angle ACD is labeled as x.

100 degrees
110 degrees
120 degrees
140 degrees

Answer 1

Given:-

• ABC is a triangle.
• 
  `\angle`BAC = 40°.
• 
  `\angle`ABC = 70°.

To Find:-

• Measure of
  `\angle`ACD.

Solution:-

➾Firstly, we will find the measure of
`\angle`ACB.

We know that,

Sum of all interior angles of a triangle = 180°.

`\rightarrow`
`\angle`BAC +
`\angle`ABC +
`\angle`ACB = 180°

`\rightarrow` 40°+70°+
`\angle`ACB = 180°

`\rightarrow` 110°+
`\angle`ACB = 180°

`\rightarrow`
`\angle`ACB = 180°-110°

`\rightarrow`
`\angle`ACB = 70°

So, the measure of
`\angle`ACB = 70°.

➾ Side BC of the triangle is extended till D. So, we have to find the measure of
`\angle` ACD.

As we know that,

Sum of any two or more angles that lie on a straight line = 180°.

So,
`\sf\angle{ACB}`+
`\sf\angle{ACD}` = 180°

`\rightarrow` 70° +
`\sf\angle{ACD}` = 180°

`\rightarrow`
`\sf\angle{ACD}` = 180°-70°

`\rightarrow`
`\sf\angle{ACD}` = 110°.

Therefore, measure of
`\sf\angle{ACD}` = 110°.

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Hope it helps you:)