Find the value of x in each triangle

Sum of all angles of a triangle is 180°

(i) 70° + 60° + x = 180°
⇒ 130° + x = 180°
∴ x = 180° – 130° = 50°

(ii) 30° + x + 90° = 180°
⇒ 120° + x = 180°
⇒ x = 180° – 120° = 60°

(iii) 40° + 40° + x = 180°
⇒ 80° + x = 180°
⇒ x = 180° – 80° = 100°

are one in this question is given that calculate the value of x in each of the following sketches and name the triangle on the basis of angles of a triangle is given to us where angle 20 50 angle C is 78 and we are to find angle A ok let me that the given angle say it is given that angle A is equal to X degrees ok Angle B is also given it is 50 degrees and angle C is also given two switches 78° so we are to find first angle then you have to determine which type of triangle this is ok so we know that according to angle sum property of triangle ok to angle sum property of triangle we know that sum of all the angles of triangle is always 180 degree it means that angle A + Angle B + angle C it is equal to 1

degrees this is a angle sum property of triangle ok now put the values a angle is 60 degrees Angle B is 50 degrees and angle C is 70 degrees and some will be equal to 180 degree ok so from here my X value will be 180 degrees - 50 degrees and minus of 78 degrees and will change because I have shifted values to RHS ok now where to find this it's calculate first we will it will be equal to 180 degrees - 50 and 70 85378 will be equal to 8 and hair 12 it will be equal to 1 28° ok and from here value of x it will be equal to 180 - 128 so it will be 10 and it will be 7 to 10 -

it is 2 and 7 - 285 so come here value of Max it is equal to 52 degrees so let's mark here angle it is 52° clearly hear Angle B is 50 degrees angle C is 70 degrees and Angle A that is it is 52 degrees so clearly it is visible here all the angles are less than 90 all the angles of the triangle are less than 90 so we know that this kind of triangle is called acute angled triangle at this point here so as a set of all the angles of the triangle are less than 90 degrees ok all the angles are less than 90 degrees so this type of triangle is called acute angle triangle therefore it is acute angle triangle so this is our final answer this is a acute angled triangle because all the sides are less than 90 degrees thank you

Triangle equations are a common part of school geometry and algebra programs. Solving for X in a triangle can encompass a number of different problems. Most commonly, X is used to represent the degree of any one of the three angles found in the triangle. Based on what type of triangle you are trying to solve for and what X represents, there are many different ways to solve for X in a triangle. Graphing the triangle can also help when solving for X.

Determine the Type of Triangle

Examine the triangle and try to locate a small square marking one of the angles. If there is a square, this is a right triangle and the angle so marked is 90 degrees.

Look to see if there are two half-circles on the base angles. If it is an isosceles triangle, the two base angles will each have a half-circle with a line through it to denote that these angles are the same size.

Look to see if there are three half-circles with lines through them at each of the angles. If there are, it is an equilateral triangle, and all three angles are the same size.

Solving for X in a Right Triangle

Add 90 degrees for the right angle to the degree measurement of the other marked angle. This measurement will be found inside the triangle at the angle that is not denoted by the X variable.

Subtract the sum of the two angles from 180 degrees. The sum of all the angles of a triangle always equals 180 degrees.

Write down the difference you found when subtracting the sum of the two angles from 180 degrees. This is the value of X.

Solving for X in an Isosceles Triangle

Locate the two base angles that are marked with half-circles with lines through them. These two angles are the same size.

Multiply the measurement given for one of the angles by two, if these angles have a measurement given. In this case you are solving for X at the vertex. Subtract the doubled measurement of the angles from 180. This is the value of the X angle at the vertex.

Subtract the measurement of the vertex angle from 180, if you are only given the measurement of the vertex angle. Divide the difference of the subtraction by two. This will give you the value of X at either of the base angles.

Solving for X in Other Triangles

Add the given degrees of the two angles provided and subtract that from 180 to solve for X in obtuse and acute triangles.

Compare the result with the visual representation of the triangle. With obtuse triangles, one angle will be larger than 90 degrees. If you are solving for this angle, be sure the figure you obtain for X is larger than 90 degrees. Acute triangles all have angles smaller than 90 degrees. Be sure that X is smaller than 90 degrees when solving for an acute triangle.

Determine if the triangle is equilateral by observing the half-circles drawn around all three of the angles with single lines drawn through all of them. If you are dealing with an equilateral triangle, all the angles equal 60 degrees and no additional mathematics is needed to determine the measurements.

Things You'll Need

• Calculator
• Graph paper

How do you find the value X in a triangle?

How do you find the value of x?