Wednesday, 18 December 2019

Angle bisector practice sum

In Triangle PQR, PQ=48 cm, PR=80 cm and QR= 112 cm. If PA, QB and RC are angle bisectors of interior angles P, Q and R respectively then find:
(i) QA, AR
(ii) PB, BR
(iii) PC, CQ.

Monday, 16 December 2019

H.O.T.S. Similarity and Co-ordinate Geometry

In triangle OAB if O (0,0) B (220,0), AO=77 mm & AB=165 mm. Bisector of angle OAB meets OB at C. Find coordinates of point C.

Saturday, 7 December 2019

Friday, 29 November 2019

Square root by long division method

4299 18481401 99999999 OK OK OK OK OK OK Step1
4 2 9 8 9 9 2 0 0 0 Step 3
Step 1 4 18 48 14 1 0 0 0 1 1 1 a= 42
+ 4 - 16 2 4 2 b= 9 10
Step 2 8 2 2 48 3 9 3 20a 840 10.01667
+ + 2 248 4 16 4 b= 9
Step 3 84 9 84 Tally - 164 5 25 5 20a +b 849
+ 9 84 14 6 36 6 (20a+b)b 7641 OK
Step 4 858 8 858 Tally 8414 7 49 7
+ 8 - 7641 8 64 8 Step 4
Step 5 8596 9 773 1 9 81 9 a= 429
+ 9 77301 100 b= 8 9
Step 6 85978 9 - 68768 Step2 20a 8580 9.009441
+ 9 8533 0 a= 4 b= 8
Step 7 859798 2 853300 b= 2 3 20a +b 8596
2 - 773802 20a 80 3.1 (20a+b)b 68768 OK
8597984 79498 0 b= 2
=2*square root 7949800 20a +b 82
8597984 - 7738182 (20a+b)b 164 OK Step 5
= 2 x  4298992 211618 0 a= 4298
0 21161800 b= 9 9
Correct Answer - 17195968 20a 85960 9.92671
3965832 b= 9
20a +b 85978
4299 (20a+b)b 773802 OK

Step 6 Step 7
a= 42989 a= 429899
b= 9 9 b= 2 2
20a 859780 9.246319 20a 8597980 2.461253
b= 9 b= 2
20a +b 859798 20a +b 8597984
(20a+b)b 7738182 OK (20a+b)b 17195968 OK

compiled trick


Wednesday, 6 November 2019

Length of angle bisector of right angle in right angled triangle


In triangle BCA, /_ C =90॰ BC=a CA=b.  Bisector of /_C meets BA at D. Find length of CD. (Hint: draw BF perpendicular on CD.)
1) Find area of the triangle BCA.
2) Find hypotenuse BA.
3)Find length of perpendicular CF on hypo. BA
4) Find BD and DA by angle bisector property / theorem.
5) Find area of triangle BCD.
6) Find BF = a sin 45॰
7) From area of triangle BCD find CD. using CD as base and BF as height.


(ab x sq root 2)/(a+b)

Tuesday, 5 November 2019

10 SSC 2020 onward pattern Q. 5 create your two own questions

Use 1+tan sq A= sec sq A to make question.
Two rational numbers are such that their difference and reciprocal of their sums is same and equal to k. Find the numbers.

Sunday, 18 August 2019

Condition for internal or external intersection of 2 chords of a circle

In a circle one chord makes two segments of a circle. If both end points of second  chord lie in only one of segments,  then the chords will intersect in the exterior of the circle. Where as, if one end of the other chord lies in one segment and the other end lies in the opposite segment then the chords will intersect in the interior of the circle. 

Sunday, 26 May 2019

My sum: Based on angles, angle bisector, cyclic quadrilateral, circle

My sum: Based on angles, angle bisector, cyclic quadrilateral, circle:

In triangle ABC /_ angle ABC (i.e. /_ ABC) equal to 90°. Ray BD is bisector of angle ABC meeting AC at D.
If ray DP is angle bisector of angle ADB and ray DQ is angle bisector of angle BDC.
Prove that:
(1) DA/DC = AB/BC
(2) (AP/PB) x (BQ/QC) = DA/DC = AB/BC
(3) Find measure of angle PDQ.
(4) Prove that quadrilateral BPDQ is cyclic.
(5) Prove that if a circle is drawn through these points i.e. B,P,D and Q, PQ will be diameter of the circle.
(6) If PQ and DB intersect at X,
prove that QX/XP = QB/BP.
(7) Hence prove that, (AP/QC) x (QX/XP) = DA/DC.

Saturday, 20 April 2019

For 9 std My sum on topic "Identities"


Hint: (1) Transpose the linear algebraic expressions to denominators.

For 9 std. My sum on Statistics topic

A data arranged in ascending order has four variates. The middle 2 variates are 29 and 31. Mean and range of the data are 30 & 14 respectively. Find first and fourth variates i.e. extremes in the data.

8 Std sum on area 2 dimensional mensuration

Find side of the square whose area is same as sum of area of two rectangles; one with length 41 and breadth 3, and other with respective dimensions as 23 and 2. All dimensions in same unit.

Sunday, 7 April 2019

Example of inverse variation, area of triangle

In triangle ABC, AB=35, AC=75 & BC=100 cm, find
(1) Area of the triangle
(2) AP, BQ and CR if these are perpendiculars from A,B and C on their opposite sides
(3) Verify example of inverse variation.
For a given triangle, height is in inverse proprtion to base.