Advertisements
Advertisements
प्रश्न
In a ΔABC, if AB = AC and ∠B = 70°, find ∠A.
Advertisements
उत्तर
Consider , ΔABC we have `∠B=70^@` and AB =AC
Since, AB A C ABC is an isosceles triangle
⇒ ∠B=∠C [Angles opposite to equal sides are equal]
⇒`∠B = ∠C = 70^@`
And also,
Sum of angles in a triangle `180^@`
⇒ `∠A+∠B+∠C=180^@`
⇒`∠A+70^@+70^@=180^@`
⇒`∠A+140^@=180^@`
⇒`∠A=180^@-140^@⇒∠A=40^@`

APPEARS IN
संबंधित प्रश्न
In a squared sheet, draw two triangles of equal areas such that
The triangles are not congruent.
What can you say about their perimeters?
In the given figure, seg AB ≅ seg CB and seg AD ≅ seg CD. Prove that ΔABD ≅ ΔCBD.

In the following figure, OA = OC and AB = BC.
Prove that:
(i) ∠AOB = 90o
(ii) ΔAOD ≅ ΔCOD
(iii) AD = CD
In the following figure, OA = OC and AB = BC.

Prove that: AD = CD
Which of the following pairs of triangles are congruent? Give reasons
ΔABC;(AB = 5cm,BC = 7cm,CA = 9cm);
ΔKLM;(KL = 7cm,LM = 5cm,KM = 9cm).
In a triangle ABC, if D is midpoint of BC; AD is produced upto E such as DE = AD, then prove that:
a. DABD andDECD are congruent.
b. AB = EC
c. AB is parallel to EC
In the figure, BC = CE and ∠1 = ∠2. Prove that ΔGCB ≅ ΔDCE.
ΔABC is isosceles with AB = AC. BD and CE are two medians of the triangle. Prove that BD = CE.
∆ABC and ∆PQR are congruent under the correspondence:
ABC ↔ RQP
Write the parts of ∆ABC that correspond to
(i) `bar"PQ"`
(ii)∠Q
(iii) `bar"RP"`
In triangles ABC and DEF, AB = FD and ∠A = ∠D. The two triangles will be congruent by SAS axiom if ______.
