Advertisements
Advertisements
प्रश्न
In a ΔABC, if ∠A=l20° and AB = AC. Find ∠B and ∠C.
उत्तर
Consider a ΔABC,
Given that ∠A = 120° and AB = AC and given to find ∠B and ∠C
We can observe that DABC is an isosceles triangle since AB = AC
⇒∠B=∠C ………(1) [Angles opposite to equal sides are equal]
We know that sum of angles in a triangle is equal to `180^@`
`⇒∠A+∠B+∠C=180^@`
⇒`∠A+∠B+∠B=180^@` [from (1)]
⇒`120^@+2∠B=180^@`
⇒`2∠B=180^@-120^@`
⇒`2∠B=60^@⇒∠B=30^@`
⇒`∠C=∠B=30^@`
APPEARS IN
संबंधित प्रश्न
In Fig. 10.40, it is given that RT = TS, ∠1 = 2∠2 and ∠4 = 2∠3. Prove that ΔRBT ≅ ΔSAT
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.
If altitudes CE and BF of a triangle ABC are equal, then AB = ....
Fill the blank in the following so that the following statement is true.
In an isosceles triangle ABC with AB = AC, if BD and CE are its altitudes, then BD is …… CE.
Which of the following statements are true (T) and which are false (F)?
Sum of the three sides of a triangle is less than the sum of its three altitudes.
Which of the following statements are true (T) and which are false (F)?
Of all the line segments that can be drawn from a point to a line not containing it, the perpendicular line segment is the shortest one.
If the measures of angles of a triangle are in the ratio of 3 : 4 : 5, what is the measure of the smallest angle of the triangle?
In the given figure, if BP || CQ and AC = BC, then the measure of x is
In ∆PQR, ∠P = 70° and ∠R = 30°. Which side of this triangle is the longest? Give reason for your answer.
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
