Q2 of 76 Page 11

In a Δ ABC, if ∠B=∠C =45°, which is the longest side?

Given that in ,

∠B = ∠C = 45o


We have to find longest side.


We know that,


Sum of angles in a triangle = 180o


∠A + ∠B + ∠C = 180o


∠A + 45o + 45o = 180o


∠A + 90o = 180o


∠A = 90o


Therefore, BC is the longest side because side opposite to greater angle is larger.


More from this chapter

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7

Fill in the blanks in the following so that each of the following statements is true.

(i) Sides opposite to equal angles of a triangle are ………


(i) Sides opposite to equal angles of a triangle are …………..


(iii) In an equilateral triangle all angles are ……….


(iv) In a Δ ABC, if ∠A=∠C, then AB = ………


(v) If altitudes CE and BF of a triangle ABC are equal, then, AB = ……..


(vi) In an isosceles triangle ABC with AB=AC, if BD and CE are its altitudes, then BD is ….CE.


(vii) In right triangles ABC and DEF, if hypotenuse AB=EF and side AC=DE, then Δ ABC ≅ Δ …….

 1

In Δ ABC, if ∠A=40° and ∠B=60°. Determine the longest and shortest sides of the triangle.

 3

In Δ ABC, side AB is produced to D so that BD=BC. If ∠B=60° and ∠A=70°, prove that:

(i) AD > CD (ii) AD > AC

 4

Is it possible to draw a triangle with sides of length 2 cm, 3 cm, and 7 cm?