Advertisements
Advertisements
Question
Find the side and perimeter of a square whose diagonal is 10 cm.
Advertisements
Solution

Let ABCD be the given square.
AC = 10 cm
Let the side of the square be x cm.
∴ AB = BC = x cm
In Δ ABC,
∠ABC = 90° ...(Angle of a square)
∴ by Pythagoras theorem,
AC2 = AB2 + BC2
∴ 102 = x2 + x2
∴ 100 = 2x2
∴ x2 = `100/2`
∴ x2 = 50
∴ x = `5sqrt2`
∴ AB = `5sqrt2` cm
∴ side of a square is `5sqrt2` cm.
Perimeter of a square = 4 × side
= 4 × `5sqrt2`
= `20sqrt2` cm
∴ Side of a square is `5sqrt2` cm and its perimeter is `20sqrt2` cm.
APPEARS IN
RELATED QUESTIONS
ABC is an isosceles triangle with AC = BC. If AB2 = 2AC2, prove that ABC is a right triangle.
ABC is an equilateral triangle of side 2a. Find each of its altitudes.
A ladder 10 m long reaches a window 8 m above the ground. Find the distance of the foot of the ladder from base of the wall.
Which of the following can be the sides of a right triangle?
2.5 cm, 6.5 cm, 6 cm
In the case of right-angled triangles, identify the right angles.
The perimeter of a triangle with vertices (0, 4), (0, 0) and (3, 0) is
(A)\[7 + \sqrt{5}\]
(B) 5
(C) 10
(D) 12
Find the length diagonal of a rectangle whose length is 35 cm and breadth is 12 cm.
Find the length of the hypotenuse of a right angled triangle if remaining sides are 9 cm and 12 cm.
If P and Q are the points on side CA and CB respectively of ΔABC, right angled at C, prove that (AQ2 + BP2) = (AB2 + PQ2)
Find the Pythagorean triplet from among the following set of numbers.
2, 4, 5
Find the Pythagorean triplet from among the following set of numbers.
9, 40, 41
The sides of the triangle are given below. Find out which one is the right-angled triangle?
11, 12, 15
Each side of rhombus is 10cm. If one of its diagonals is 16cm, find the length of the other diagonals.
In ΔABC, AD is perpendicular to BC. Prove that: AB2 + CD2 = AC2 + BD2
To get from point A to point B you must avoid walking through a pond. You must walk 34 m south and 41 m east. To the nearest meter, how many meters would be saved if it were possible to make a way through the pond?
Find the unknown side in the following triangles
An isosceles triangle has equal sides each 13 cm and a base 24 cm in length. Find its height
Prove that the area of the semicircle drawn on the hypotenuse of a right angled triangle is equal to the sum of the areas of the semicircles drawn on the other two sides of the triangle.
The top of a broken tree touches the ground at a distance of 12 m from its base. If the tree is broken at a height of 5 m from the ground then the actual height of the tree is ______.
Two rectangles are congruent, if they have same ______ and ______.
Points A and B are on the opposite edges of a pond as shown in the following figure. To find the distance between the two points, the surveyor makes a right-angled triangle as shown. Find the distance AB.

