Question

The angle of a triangle are (x+15), (2x-20) and 2x. What are the actual angle measures of the triangle?

Answer 1

Okay so here's what you do,

Add them,

$2x + x + 15 + 2x - 20 = 180$

Collect the like terms,

2x + x +2x = 5x

$5x + 15 - 20 = 180$

Calculate the sum / difference,

15 - 20 = - 5

$5x - 5 = 180$

Move constant to the right side and change its sign,

$5x = 180 + 5$

Calculate by adding,

$5x = 185$

Divide both sides of the equation by 5,

$5x \div 5 = x$

$185 \div 5 = 37$

$x = 37$

We're not done yet, x=37, now let's find out the measurements of each side.

To do this, simply substitute all expressions with x being 37,

$2x = 2(37) = 74$
$x + 15 = 37 + 15 = 52$
$2x - 20 = \: 2(37) - 20 = 54$

Remember, a triangle always has 180° and do the measurements add up to 180??

$52 + 54 + 74 = 180$

Yes, they do meaning it's correct & reasonable!

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I hope that helps you out!!

Any more questions, please just ask me!!

~ Zoey