Question
In a triangle ABC, a point D lies on AB and points E and
F lie on BC such that DF is parallel to AC and DE is parallel to AF. If BE = 4 cm. EF = 6cm. then find the length (in cm) of BC.Solution
Δ BDE ~ Δ BAF -------- (i) Δ BDF ~ Δ ABC ------- (ii) From (i), => x/(x+y) = 4/10 ------- (iii) From (ii), => x/(x+y) = 10/(10+t) ------- (iv) Now using (iii) in (iv) we get, => 4/10 = 10/(10+t) => 20 + 2t = 50 => t = 15 Therefore, BC = 4 + 6 + 15 = 25 cm
The lateral surface area of a regular tetrahedron is 75√3 cm². Determine the volume of the tetrahedron.
Find the area of sector of a circle whose radius is 21 cm and angle subtended by the sector at centre of circle is 45 ° .
The perimeter of a rectangle is 64 cm. The side of a square is equal to the average of the rectangle’s length and breadth. Find the area of the square...
- If the edge of the cube is increased by 30%, then find the percentage increase in the volume of the cube.
If the length of a rectangle is increased by 25% and its breadth is decreased by 15%, then the area of the rectangle will be increased or decreased by h...
The radii of two solid right circular cylinders are 11 cm and 9 cm respectively and their heights are (h+1) cm and (2h+1) cm respectively. If the areas ...
The volume of a cone is 128π cubic centimeters. If the radius of the base is 4 cm, find the height of the cone.
A cone has a radius of 5 cm and a slant height of 13 cm. Find the total surface area of the cone.[Take π = 3.14 ]
If x4 – 62x2 + 1 = 0, then a value of x 3 + x -3 can be:
The base of a triangle is 18 cm and height is 15 cm. The height of another triangle of double the area having the base 27 cm is:
Relevant for Exams:
