in any triangle, the sum of the measures of the angles is 180. given abc with mLA = 35 and mLB=90, write and solve an equation to find mLC

There are two methods to find the measure of the third interior angle of the triangle.

The first is to set the interior angle values equal to 180 and solve for the unknown angle.

180 = 35 + 90 + m∠C

Collect like terms.

180 = 125 + m∠C

Subtract 125 from both sides.

55 = m∠C

The second method is to simply subtract the two known interior angle values from the known sum of all the interior angle values.

180 - 35 - 90 = m∠C

180 - 35 - 90 = 55

Both render the same result, although the second is far faster.

Answer:

m∠C = 55°

So you could do it by 180=35+90+c

Then you would add 35 and 90 to get 125

Then you would subtract 125 from both sides

That would leave you with 55=c

So then the measure of angle C would be 55

C=55