Right Angle

How to find the measure of the given angle by using the measure of a right angle: definition, 1 example, and its solution.



A right angle is an angle
whose degree measure is 90.
Its symbol is [∟].

So if ∠A is a right angle,
then m∠A = 90.




It says
the measure of the whole angle, m∠AOC, is 115.

So draw ∠AOC
and write 115º.

See the given angles.

The measure of the purple angle is [4x + 1].

The blue angle is a right angle.
So the measure of the blue angle is [90].

The purple angle and the blue angle
form the brown angle.
Its measure is [115].

So [4x + 1] + [90] = [115].

+1 + 90 = +91

Move +91 to the right side.

Then 4x = 24.

Divide both sides by 4.

Then x = 6.

So x = 6 is the answer.