CBSE > Class 09 > Mathematics | CBSE Board | Homework Help

It is given that, ∠Q = 2∠PRQ. In ΔPQR, ∠PQR + ∠PRQ + ∠RPQ = 180° ⇒ 2∠PRQ + ∠PRQ + 90° = 180° ⇒ 3∠PRQ = 180° − 90° = 90° ⇒ ∠PRQ = 90°/30=30° … (1) ∴ ∠PQR = 2 × 30° = 60° … (2) Now, extending QP to S such that QP = PS, and joining RS. P /|\ / | \ / | \ / | \ / | \ / | \ / | \ / | \ / | 90° \ /______ |__________\ S Q R In ΔRPQ and ΔRPS: RP = RP (Common) ∠RPQ = ∠RPS = 90° PQ = PS (by construction) ∴ ΔRPQ ≅ ΔRPS (by SAS congruence rule) ⇒ RQ = RS and ∠PRQ = ∠PRS (CPCT) Now, ∠SRQ = ∠PRQ + ∠PRS = 2∠PRQ = 2 × 30° = 60° [from (1)] By CPCT, we obtain ∠PQR = ∠PSR ∴ ∠PSR = 60° [from (2)] Therefore, ΔQRS is an equilateral triangle. ⇒ QR = RS = SP = 10 cm ∴ SP = PQ = 10cm/2=5cm On applying Pythagoras theorem to ΔPQR, we obtain RP2 + PQ2 = QR2 ⇒ RP2 + (5 cm)2 = (10 cm)2 ⇒ RP2 + 25 cm2 = 100 cm2 ⇒ RP2 = 75 cm2 ⇒ RP =5√3cm ∴ Perimeter of ΔPQR = RP + PQ + QR =(5√3+5+10)cm = (5 × 1.73 + 15) cm = 23.65 cm Thus, the perimeter of ΔPQR is 23.65 cm. The correct answer is C.

1Thank You

Neha Gautam 5 years, 2 months ago

Nahi aata muje

0Thank You

ANSWER

Ab parallel CD find angle poq angle Apo angle oqd

Posted by Varsha Kanwar 5 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

In triangle ABC, angle A - angle B = 33° and angle B - angle C = 18° find is measure of each angle of triangle

Posted by Rishika S 11 5 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Gaurav Seth 5 years, 2 months ago

Given :

In a triangle ABC :

∠ A - ∠ B = 33

∠ B - ∠ C = 18

We have find values of all angle :

We know sum of all interior angle of triangle is 180 .

∠ A + ∠ B + ∠ C = 180 .. ( ii )

We have :

∠ A - ∠ B = 33

∠ B - ∠ C = 18

Rewrite as :

∠ A = 33 + ∠ B

∠ C = ∠ B - 18

Now putting

33 + ∠ B + ∠ B + ∠ B - 18 = 180

3 ∠ B + 15 = 180

3 ∠ B = 165

∠ B = 55

Putting values of B in :

∠ A - ∠ B = 33

∠ B - ∠ C = 18

∠ A = 88

∠ C = 37 .

Answer:

∠ A = 88

∠ B = 55

∠ C = 37 .

1Thank You

ANSWER

If any student will select basic Maths then can he take Maths Subject in 11 th &12 th std? What are the limitations for him? Can anybody explain this ?

Posted by Sandeepkumar Jain 5 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Prince Jain 5 years, 2 months ago

No if you take basis you are not able to take maths in class 11 as well as in class 12

1Thank You

ANSWER

How can be find primefactorization of 72, 800, 18

Posted by Anshika Kumari 5 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Gaurav Seth 5 years, 2 months ago

Prime factorization is the decomposition of a composite number into a product of prime numbers.

Prime factorization of 72: 2³ × 3²

Prime factorization of 800: 2⁵ × 5²

Prime factorization of 18: 2 × 3²

1Thank You

ANSWER

What are the properties of a 1.trapezium 2.rhombus 3.parallelogram 4. Rectangle and square

Posted by My Cbse Guide ?? 5 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Gaurav Seth 5 years, 2 months ago

Trapezium:

Like other quadrilaterals, the sum of all the four angles of the trapezium is equal to 360°
A trapezium has two parallel sides and two non-parallel sides
The diagonals of regular trapezium bisect each other
The length of the mid-segment is equal to half the sum of the parallel bases, in a trapezium
Two pairs of adjacent angles of a trapezium formed between the parallel sides and one of the non-parallel side, add up to 180 degrees.

Rhombus:

All sides of the rhombus are equal.
The opposite sides of a rhombus are parallel.
Opposite angles of a rhombus are equal.
In a rhombus, diagonals bisect each other at right angles.
Diagonals bisect the angles of a rhombus.

Parallelogram:

The opposite sides are congruent.
The opposite angles are congruent.
The consecutive angles are supplementary.
If anyone of the angles is a right angle, then all the other angles will be the right angle.
The two diagonals bisect each other.
Each diagonal bisects the parallelogram into two congruent triangles.

0Thank You

ANSWER

Is standard maths very difficult or average

Posted by Shruti Padhan 5 years, 2 months ago

CBSE > Class 09 > Mathematics

3 answers

Abhinandan Dubey 5 years, 2 months ago

Some lessons are very difficult

1Thank You

Palak Pandey 5 years, 2 months ago

Yeah average but I think in our textbook 3 chapters are too bouring and difficult also quadrilateral , parellogram and circle?????

1Thank You

Kanishka Chauhan 5 years, 2 months ago

Average

0Thank You

ANSWER

(3x-2)(2x³+3x²)

Posted by Purbanhi Mitra 5 years, 2 months ago

CBSE > Class 09 > Mathematics

2 answers

Kishan Kishan 5 years, 2 months ago

(13)21

0Thank You

Siddhi Karnani 5 years, 2 months ago

3x(2x³+3x²) -2(2x³+3x²) (6x⁴+9x³) - (-4x³-6x²) 6x⁴+9x³+4x³+6x² 6x⁴+13x³+6x²

2Thank You

ANSWER

Find the ratio of the total surface area and lateral surface area of a cube

Posted by Sarah Sana 5 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Kumkum Sharma 5 years, 2 months ago

Cjiamkm

0Thank You

ANSWER

Find p(x)=5-y

Posted by Suresh Chand 5 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

Find five irrational numbers between 2017 and 2018

Posted by Krrish Prasad 5 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

x + y = 36 where x = 10 find value of z

Posted by Kartikeya Bohra 5 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Kartikeya Bohra 5 years, 2 months ago

z = 0 because it is not given in question

0Thank You

ANSWER

Rationalise the denominator 16/√41-5

Posted by Lija Gigi 5 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

Simplify by rationalising denominators 2+3√5/2-3√5

Posted by Lija Gigi 5 years, 2 months ago

CBSE > Class 09 > Mathematics

3 answers

Arpit Agnihotri 5 years, 2 months ago

-49-12√5

1Thank You

Kedarnath Acharya 5 years, 2 months ago

-49-12root5

1Thank You

Trishla Jain 5 years, 2 months ago

-49 -12root5

1Thank You

ANSWER

If ∠A–∠B = 33° , ∠B–∠C=18° of a ∆ABC, then ∠C is

Posted by Sashi Kumar 5 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

Five rational number between 2/3 and 5/3

Posted by Rajesh Singh 5 years, 2 months ago

CBSE > Class 09 > Mathematics

2 answers

Asmi Hingole 5 years, 2 months ago

10/15,11/15,12/15,13/15,14/15

0Thank You

Pushkar Kamble 5 years, 2 months ago

Five rational numbers between 2/3 and 5/3 are 13/18,14/18,15/18,16/18,17/18

1Thank You

ANSWER

If X=1/2-√3, find the value of x2-4x+1

Posted by Divyanshi Mor 5 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

Name the quadrilateral ABCD given alongside Find value of x If OD=7x+6 , OB=4x +30

Posted by Unnati Kumawat 5 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

Find 5 rational no. between -3/5and1/6

Posted by Khushboo Singh 5 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Abhay Singh 5 years, 2 months ago

-17/30 -16/30 -15/30 -14/30 -13/30

0Thank You

ANSWER

Two points with coordinates(2,3) and (2,-1) lie on a line , parallel to which axis.justify your answer

Posted by Arshbir Singh 5 years, 2 months ago

CBSE > Class 09 > Mathematics

3 answers

Kedarnath Acharya 5 years, 2 months ago

Y-axis

0Thank You

Yogita Ingle 5 years, 2 months ago

Equation of line in two point form is given by y−y1/ (x−x1)=y2−y1 / (x2−x1)

∴ equation of line for (2,3) and (2,-1) is

(y−3)/ (x−2)=(3+1)/(2−2)

(y−3)/ (x−2)= 4/0

⟹ 4(x−2) =0

i.e. x=2

Here the abscissa for P as well as Q is 2 i.e same. So both the points lie on the line x=2.

Hence, PQ is parallel to Y-axis.

0Thank You

Suraj Yadav, Roll 44,Class 9 E, 5 years, 2 months ago

x and you axis

0Thank You

ANSWER

x - 3y = 6

Posted by Diya Saluja 5 years, 2 months ago

CBSE > Class 09 > Mathematics

3 answers

Divyanshi Agrawal 5 years, 2 months ago

x-y=6/3 =2

1Thank You

Divyanshi Agrawal 5 years, 2 months ago

x-y=6/3

1Thank You

Rajneesh Kumar Rajneesh 5 years, 2 months ago

X =2

0Thank You

ANSWER

For what c.p.c.t is used in triangle

Posted by Devesh More 5 years, 2 months ago

CBSE > Class 09 > Mathematics

3 answers

Devesh More 5 years, 2 months ago

What are corresponding parts of congruent triangle?

0Thank You

Suraj Yadav, Roll 44,Class 9 E, 5 years, 2 months ago

for congruent

0Thank You

Rajneesh Kumar Rajneesh 5 years, 2 months ago

Corresponding parts of congruent triangle

0Thank You

ANSWER

Find area of triangle whose two sides are 18 cm and 10 cm .periemeter is 42 cm

Posted by P R I N C E 5 years, 2 months ago

CBSE > Class 09 > Mathematics

3 answers

12345 . 5 years, 2 months ago

Answer is 21 underroot 11 cm sq.

1Thank You

Palak Pandey 5 years, 2 months ago

I solve it with the herons formula and the answer is 11√21 cm^2

0Thank You

Gaurav Seth 5 years, 2 months ago

Given,
Side a=18cm
Side b=10cm
Perimeter=42cm=a+b+c
:. Putting value
42=18+10+c
42=28+c
42-28=c
14=c
Now,
S=(a+b+c)/2
:. Putting value
S=42/2
S=21
Now according to Heron's formula-
Area of a triangle
=√{s(s-a)(s-b)(s-c)}
:. Putting value
=√{21(21-18)(21-10)(21-14)}
=√{21(3)(11)(7)}
=√4851
=21√11cm²

1Thank You

ANSWER

2x+(_3)+4

Posted by Adarsh Tiwari 5 years, 2 months ago

CBSE > Class 09 > Mathematics

3 answers

Shrutee Kumari 5 years, 2 months ago

2x+(-3)+4=2x-3+4=2x+1 x=-1/2= - 0.5

0Thank You

Palak Pandey 5 years, 2 months ago

If it is a sign of (- )then the value X=-1/2

0Thank You

Palak Pandey 5 years, 2 months ago

What is it written before three??

0Thank You

ANSWER

Is (x+1) a factor of polynomial x/665 + x/556 + x/488 + x/412 + x/335

Posted by Sakhi Ambekar 5 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

What is arc in circle??

Posted by Palak Pandey 5 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Yogita Ingle 5 years, 2 months ago

The arc of a circle is defined as the part or segment of the circumference of a circle. A straight line that could be drawn by connecting the two ends of the arc is known as a chord of a circle. If the length of an arc is exactly half of the circle, it is known as a semicircular arc.