Mathematics
Which of the following is correct? 1. If D is a point on side AB of ΔABC such that AD : DB = 5 : 2 and E is a point on BC such that DE ∥ AC, then ar(ΔABC) : ar(ΔDBE) = 9 : 4. 2. If the areas of two similar triangles are in the ratio 25 : 64, then their perimeters are in the ratio 5 : 8. 3. In the adjoining figure if AB ∥ CD, then ΔAOB ΔCOD. 4. In the adjoining figure, if D and E are the mid-points of AB and AC respectively, then ar(ΔADE) = × ar(ΔABC).
Related Questions
A street lamp is fixed on a lamp-post at a height of 3.3 m from the ground. A boy 110 cm tall walks away from the base of this lamp post at a speed of 0.8 m/s. The length of the shadow of the boy after 4 seconds is:
1.1 m
1.6 m
2.1 m
2.6 m
The lengths of the sides of triangle P are 3, 4 and 5 units. Another triangle Q, which is similar to P, has one side of length 60 units, what is the smallest possible perimeter of triangle Q?
120 units
144 units
180 units
240 units
In the given figure, D, E and F are the mid-points of the sides BC, AC and AB respectively of ΔABC. Then which of the following does not hold true?
ΔAFE ∼ ΔABC
ΔFBD ∼ ΔABC
ΔEDC ∼ ΔABC
ΔDFE ∼ ΔABC
