Advertisements
Advertisements
प्रश्न
In the given figure, if l1 || l2, the value of x is

पर्याय
\[22\frac{1}{2}\]
30
45
60
Advertisements
उत्तर
In the given problem, l1 || l2
We need to find the value of x

Here, as l1 || l2 , using the property, “consecutive interior angles are supplementary”, we get
∠DAC + ∠ECA = 180°
a + a+ b+ b =180°
2a + 2b = 180°
`a + b = (180°)/2`
a + b = 90° ..........(1)
Further, applying angle sum property of the triangle
In ΔABC
∠BAC + ∠BCA + ∠ABC =180°
a + b + ∠ABC = 180°
90 + ∠ABC = 180° (using 1)
∠ABC = 180° - 90°
∠ABC = 90°
Now, AB is a straight line, so using the property, “angles forming a linear pair are supplementary”, we get,
x + x + ∠ABC = 180°
2x + 90° = 180°
2x = 180° - 90°
`x = (90°)/2`
x = 45°
Thus, x = 45°
APPEARS IN
संबंधित प्रश्न
In an isosceles triangle ABC, with AB = AC, the bisectors of ∠B and ∠C intersect each other at O. Join A to O. Show that:
- OB = OC
- AO bisects ∠A
ABC is an isosceles triangle in which altitudes BE and CF are drawn to equal sides AC and AB respectively (see the given figure). Show that these altitudes are equal.

If the base of an isosceles triangle is produced on both sides, prove that the exterior angles so formed are equal to each other.
In figure, AB = AC and DB = DC, find the ratio ∠ABD : ∠ACD
Determine the measure of each of the equal angles of a right-angled isosceles triangle.
Prove that the medians of an equilateral triangle are equal.
Which of the following statements are true (T) and which are false (F):
The measure of each angle of an equilateral triangle is 60°
Fill the blank in the following so that the following statement is true.
In a ΔABC if ∠A = ∠C , then AB = ......
Fill in the blank to make the following statement true.
Difference of any two sides of a triangle is........ than the third side.
In the given figure, x + y =

In the given figure, what is y in terms of x?

The angles of a right angled triangle are
It is given that ∆ABC ≅ ∆FDE and AB = 5 cm, ∠B = 40° and ∠A = 80°. Then which of the following is true?
AD is a median of the triangle ABC. Is it true that AB + BC + CA > 2AD? Give reason for your answer.
M is a point on side BC of a triangle ABC such that AM is the bisector of ∠BAC. Is it true to say that perimeter of the triangle is greater than 2 AM? Give reason for your answer.
CDE is an equilateral triangle formed on a side CD of a square ABCD (Figure). Show that ∆ADE ≅ ∆BCE.

Bisectors of the angles B and C of an isosceles triangle ABC with AB = AC intersect each other at O. Show that external angle adjacent to ∠ABC is equal to ∠BOC
Show that in a quadrilateral ABCD, AB + BC + CD + DA > AC + BD
