Question

Find the measure of the angle in the following figure

A) a= 117º

B) a= 63º

C) a= 98º
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Answer 1

A) a = 117°, as the total measure of the figure is 180°, so you subtract the sum of the known angles (20°+43°) from 180° to equal 117°

Answer 2

When looking at a straight angle, we know that it must be 180°. So, we set up the equation:

`\sf \: a + 20° + 43° = 180°`

We operate:

`\sf \: to + 63° = 180°`

We subtract 63° in both members and I am left with:

`\sf \: a + 63° - 63° = 180° - 63°`

`\sf \: a = 117°`

So the answer is part A) a= 117°