Question

Please give Q 2 and 3.. it's urgent ​

Answer 1

Q2.If one angle of a triangle is equal to the sum of other two angles show that the triangle is a right angled triangle?

A2.The 3 angles add up to 180 degrees so if one of them is equal to the sum of the other two, it obviously has to be a right angle (90 degrees;) with the sum of the other 2 angles also equal to 90 degrees. It is a right angled triangle. In such a triangle, one angle is always a right angle, i.e., 90 degrees.

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Q3.In the given figure if DE//BC, angle A = 60°,angle B=70° find angle C,angle D and angle E

A3.angle C=30°

angle D=20°

angle E=20°

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Answer 2

Answer:

1.) Let angle= x

other two angles= y and z

By using angle sum property of triangle:-

x+y+z=180

We are given that one angle is the sum of other two angles.

So, we can write y+z= x

x+x=180

2x=180

x=

x=90

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2.) By angle sum property of triangle:-

∠A + ∠B + ∠C= 180°

60° + 70° + ∠C= 180°

130° + ∠C= 180°

∠C= 180°-130°

As, ∠B is corresponding to ∠D

Therefore,

∠B= ∠D

70°= ∠D

As, ∠C is corresponding to ∠E

Therefore,

∠C= ∠E

50°= ∠E

Therefore, ∠C= 50°, ∠D= 70° and ∠E= 50°

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3.) As y and 70° are linear pair

Therefore,

y+70°= 180°

y= 180°-70°

Let an angle z to be present on third angle of this triangle.

Therefore, by Angle sum property:-

y+40°+z= 180°

110°+40°+z= 180°

150°+z= 180°

z= 180°-150°

As, z and x are linear pair

Therefore,

z+x= 180°

30°+x= 180°

x= 180°-30°

Therefore, value of x= 150° and y= 110°