Elitmus
Exam
Numerical Ability
Area and Volume
triangle ABC is an isosceles triangle. if AB changed to 3AB and AC changed to 3AC without changing the measure of angle A. what is the change in area
Read Solution (Total 5)
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- AB and AC are adjecent sides of trianlge ABC have common angle A.
we know area of any trianlge = product of two adjecent side * SIN(angle bet them)
i.e area = AB*AC*SIN(A)
hence new area = (3AB)*(3AC)*SIN(A)
= 9 times old area - 9 years agoHelpfull: Yes(43) No(0)
- It is an isosceles triangle.Therefore, 3AB=3AC and angle is same.
Then, AB:AC:BC:h = 3AB:3AC:3BC:3h where,h is height [property of isocl. trngl]
area of any triangle = 1/2 * base * height
Now,
area of small trngl : area of large triangle
1/2 *BC*h : 1/2*3BC*3h [1/2 cancels 1/2 and BC & h cancels BC & h]
1:9
Change in area=900%
- 9 years agoHelpfull: Yes(3) No(4)
- area of isoceles triangle=AB/4( (4AC^2-AB^2)^1/2)
so ans is = 3 time of old area - 9 years agoHelpfull: Yes(1) No(7)
- AB->3AB & AC->3AC
area2/area1=3*3/1*1=9times - 8 years agoHelpfull: Yes(1) No(0)
- 9 times is correct ans
- 8 years agoHelpfull: Yes(1) No(2)
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