CBSE - Triangles

1 Triangles 

ABC and BDE are two equilateral triangles such that D is the mid point of BC. AE intersects BC in F. Then ar (BDE) is equal to

1) 2ar (ABC)
2) 1/4ar (ABC)
3) 1/2ar (ABC)
4) ar (ABC)

2 Triangles 

The hypotenuse of a right triangle is 10cm and radius of the inscribed circle is 1 cm. The perimeter of the triangle is:

(1) 15 cm 
(2) 22 cm
(3) 24 cm 
(4) 18 cm
 

3 Triangles 

The ratio of the length of a side of an equilateral triangle and its height is: 

(1) 2 : 1 
(2) 1 : 2  
(3) 2 : √3
(4) √3 : 2

4 Triangles 

In the followign figure QT perpendicular to  PR and QS = PS. If <TQR = 40° and <RPS = 20° then value of x is :

1) 80°
2) 25°
3) 15°
4) 35°

5 Triangles 

In an equilateral triangle ABC if AD ꓕ BC, then:

(1) 2AB² = 2AD²
(2) 4AB² = 3AD²
(3) 3AB² = 4AD²
(4) 2AB² + 2AD²

6 Triangles 

ABC and BDE are two equilateral triangles such that D is the mid-point of BC. Ratio of the areas of triangles ABC and BDE is :

(1) 2 : 1  
(2) 1 : 2 
(3) 4 : 1 
(4) 1 : 4