Question

1) detemine whether the triangle whose lengths of side are4,5,6 is aright angled triangle.
2)find the unknown angle in the following figure .

Answer 1

Answer:

Scalene and right

Explanation:

Since all three sides have different lengths, it is a scalene triangle. But, we must test for a second feature. Using Pythagorus' theorem

a

2

+

b

2

=

c

2

we find

3

2

+

4

2

=

5

2

9 + 16 = 25

So, these sides also cause it to be a right triangle.

Answer 2

1) In a right angled triangle if the sum of square of two smaller sides is equal to the square of third side then the angle opposite to the third side is right angle.

Here:

(4)^2 + (5)^2 is not equal to (6)^2 so the triangle is not a right angled triangle.

2) (x) + (2x) + 90° = 180°

(Angle sum property)

3x + 90° = 180°

3x = 180° - 90°

3x = 90°

x = 90°/3

x = 30°

3x = 3 × 30° = 60°