# One Acute Angle of a right angled triangle is double the other. If the length of its hypotenuse is 10 cm, then its area is:

- 2 75 cm²
- 25 cm²
- 3 2 25 cm²
- None of these

**Answer: (4) None of these**

**Solution:-**

In the right triangle –

One acute angle of a right angled triangles is double the other.

Then the angles are 30 degree and 60 degree.

Sin 30 degree = AC/10

1/2 = AC/10

AC = 10/2

AC = 5 cm

And Cos 30 degree = AB/10

sqrt.3/2 = AB /10

AB = 10 sqrt.3/2

AB = 5 sqrt.3

**Formula –
The area of the triangle = base x height/2**

Then the area of the right angle triangle = 5 x 5 sqrt.3/2

= 25sqrt.3/2 cm square.

Hence, the correct answer is 25sqrt.3/2 cm square.