how to calculate angle of a triangle which has 2 equal lenght line and 3rd line which is a bit longer?

Question

Isosceles triangles

Answer 1

You should know that a triangle is a 180° polygon. You can have this equation for solving the 3 angles of a triangle( 2 angles= the same and 1 angle a little bit longer)


Let x = one angle
x = another angle with the same measure on the first
x+3 = refers to the 3rd angle w/c is a little bit longer
(Take note that i just used x+3 to have an exact answer you can use every number that you want but remember to use a positive one ^_^)

Equation:
x+x+x+3=180° ( just like what ive said the measure of the angles of a triangle is equal to 180°)
3x=180-3
3x=177
3x/3=177/3
x-59

therefore:
x=59°(1st angle)
x=59°(2nd angle)
x+3= 62° (3rd angle)

Add: (Be sure that it is equal to 180°)
59°+59°+62°=?180°
180°=180°
True

If you use x+1 the answers will go like this
x=59.67
x=59.67
x+1= 60.67

answer will be 180.01 you will not get the exact answer because youve rounded it off round off 180.01 and the answer is also 180)

This solution shows that the 2 angle will never be 60 or more and the third angle will never be 60 or less..!!

But your answer should be based on the question you should know how much longer is the third angle than the 2 angles!

Take note the i answered this question:
(The triangle has 2 angles with the same measure and the third angle is 3° more than the the angles find the measure of the angles?)^_^!!

Hope that this helps!! email me for some problems thnkz!!
^_^!!

Answer 2

'Tis better that we let first the triangle be ABC. We assign opposite sides: AB = c, BC = a and AC = b.(or simply c is the side opposite angle C, b is the side opposite angle B...)

From your condition, we will assign a = b, c > a and c > b.

From this, and by the Isosceles Triangle Theorem (if 2 sides of a triangle are congruent, then the angles opp. them are also congruent), we can see that A = B.

From the cosine law,
c² = a² + b² - 2ab cos C

Since a = b, we substitute a for all b.
c² = a² + a² - 2(a)(a) cos C

Thus,
c² = 2a² - 2a² cos C

Factor out:
c² = 2a²(1 - cos C)

Divide
c²/2a² = 1 - cos C

We have
cos C = 1 - c²/2a²

Thus, we have
C = arccos (1 - c²/2a²)

Since
A + B + C = 180 degrees, and A = B, so
2A + C = 180 degrees
A = 90 degrees - C/2
A = 90 degrees - arccos (1 - c²/2a²)/2

Also,
B = 90 degrees- arccos (1 - c²/2a²)/2

We now have:
A = 90 degrees - arccos (1 - c²/2a²)/2
B = 90 degrees - arccos (1 - c²/2a²)/2
C = arccos (1 - c²/2a²)

^_^

Answer 3

It is an isosceles triangle.
Two of the angles would be equal. And the angle between the equal sides would be different.
But we need to know atleast 2 elements of the triangle.

Answer 4

The sum of the angles of a triangle add up to 180, irregardless of shape. two even lines rqual two even angles and the third would correspond with the line that is odd, (longer/wider,shorter/narrower).

Answer 5

To solve the triangle we must know two sides and an angle or three sides.

Answer 6

if you know the value of sides of the triangle you can use the cosine law,
a^2 = b^2 + c^2 - 2bc*cosØ
whereas Ø is opposite to the side a.

Answer 7

as suggested above, you should use the dot product, locate 2 vectors, one on each and every line, then use the dot product formula to get your attitude. or a fashion it quite is in simple terms as effortless: for first line locate the attitude (call it a) using tan(a)=2 then for the 2d line, locate the attitude (call it b) using tan(b)=0.5 note that because the 2d line is way less steep you receives a smaller answer for b. Then to locate your attitude do in simple terms a-b

Answer 8

Let your triangle be ABC, with AB = BC.
Then B = 2arcsin(AC/2AB), and
A = C = (180-B)/2
AC can be any length less than 2AB.