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.
Definition
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.
Example
Solution
Solution (Detail)
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.