What Are The Area Unchanged The Height of The Triangle
The base of a triangle is increased by 10%. To keep the area unchanged the height of the triangle is to be decreased by ?
- 100/11%
- 100/9%
- 11%
- 9%
Answer: (1) 100/11%
Explanation:-
The area of a triangle = base x height/2
Let the height decreased by X %
According to the question,
(base x 110/100) (height [100 – X)/100]/2 = base x height /2
11 base x height(100 – X)/1000 x 2 = base x height/2
11 x (100 – X)/1000 = 1
100 – X = 1000/11
– X = 1000/11 – 100
– X = (1000 – 1100)/11
– X = – 100/11
X = 100/11
Hence, the answer is (1) 100/11%