Advertisements
Advertisements
प्रश्न
Let ∆ ABC ∽ ∆ DEF and their areas be respectively, 64 cm2 and 121 cm2. If EF = 15⋅4 cm, find BC.
उत्तर
Given:
Δ ABC ∼ Δ DEF
We know the ratio of the areas of two similar triangles is equal to the square of the ratio of their corresponding sides.
`("ar"Δ"ABC")/("ar"Δ"DEF") = ("BC"/"EF")^2`
⇒ `64/121 = ("BC"/15.4)^2`
⇒ `(8/11)^2 = ("BC"/15.4)^2`
⇒ `8/11 = "BC"/15.4`
⇒ `"BC" = (8 xx 15.4)/11 = 11.2` cm
Thus, BC = 11.2 cm.
APPEARS IN
संबंधित प्रश्न
Find the roots of the following quadratic equation by factorisation:
x2 – 3x – 10 = 0
Solve the following quadratic equations by factorization:
48x2 − 13x − 1 = 0
A girls is twice as old as her sister. Four years hence, the product of their ages (in years) will be 160. Find their present ages.
Solve of the following equations, giving answer up to two decimal places.
3x2 – x – 7 =0
The sum of natural number and its positive square root is 132. Find the number.
A farmer wishes to grow a 100m2 rectangular vegetable garden. Since he was with him only 30m barbed wire, he fences 3 sides of the rectangular garden letting the compound of his house to act as the 4th side. Find the dimensions of his garden .
Write the number of zeroes in the end of a number whose prime factorization is 22 × 53 × 32 × 17.
Solve the following equation by factorization
`(1)/(2a + b + 2x) = (1)/(2a) + (1)/b + (1)/(2x)`
The lengths of the parallel sides of a trapezium are (x + 9) cm and (2x – 3) cm and the distance between them is (x + 4) cm. If its area is 540 cm2, find x.
The polynomial equation x(x + 1) + 8 = (x + 2) (x – 2) is:
