Question

in triangle abc ,right angled at c , find the value of cos(a+b)

Answer 1

since ABC is right angled and angle C is 90°

therefore,

A+B=180°-C

A+B=180°-90°

A+B= 90°

Therefore,cos (A+B)=cos90°
=0

Answer 2

In a triangle ABC is a right angle triangle with C at right angle the value of Cos(A+B) is Zero

Step-by-step explanation:

Given : The triangle ABC is a right angle triangle with C at right angle

To find: The value of Cos(A+B)

Solution:

we know that the sum of all the three interior angles of a triangle is always equal to 180 degree.

Right angled triangle:

"A right-angled triangle is one in which one of the interior angles is 90 degrees or one of the angles is a right angle. This triangle is also known as a right triangle or a triangle with a 90-degree angle."

Therefore,

∠A + ∠B + ∠C = 180°

∠A + ∠B + 90° = 180°

∠C  = 90 (it is a right angle triangle)

∠A + ∠B = 180° - 90°

∠A + ∠B = 90°

cos (A+B) = cos 90°

Using the trio0nometric ratio of angles,

cos 90° = 0

Final answer:

Therefore, the values of Cos(A+B) is zero

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