Loading [MathJax]/jax/output/HTML-CSS/jax.js

Diagonals of a Square are Equal in Length and they Meet at Right Angles

Here we will prove that in a square, the diagonals are equal in length and they meet at right angles.

Given: PQRS is a square in which PQ = QR = RS = SP, and ∠QPS = ∠PQR = ∠QRS = ∠RSP = 90°.

To prove: PR = QS and PR ⊥ QS

Proof:

            Statement

            Reason

1. In ∆SPQ and ∆RQP,

(i) SP = QR


(i) Given

(ii) PQ = PQ

(ii) Common side

(iii) ∠SPQ = ∠PQR

(iii) Given

(iv) ∆SPQ ≅ ∆RQP

Therefore, QS = PR    (Proved)

(iv) By SAS criterion of congruency. CPCTC.

2.

(v) ∠PQS = ∠PSQ


(v) In ∆PQS, PQ = PS

(vi) ∠PQS + ∠PSQ = 90°.

(vi) In ∆QPS, ∠QPS = 90° and sum of three angles of a triangle is 180°.

(vii) ∠PQS = 90°2 = 45°

(vii) By statements (v) and (vi).

(viii) ∠QPR = 45°

(viii) Similarly as (vi) and (vii) for the ∆PQR.

(ix) ∠POQ = 180° - (PQO + ∠QPO)

               = 180° - (45° + 45°)

               = 180° - 90°

               = 90°

Therefore, OP ⊥ OQ

Therefore, ∠POQ = 90°

Therefore, PR ⊥ QS       (Proved)

(ix) By statements (vii), (viii) and the sum of the angles of ∆POQ is 180°.






9th Grade Math

From Diagonals of a Square are Equal in Length & they Meet at Right Angles to HOME PAGE




Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.



New! Comments

Have your say about what you just read! Leave me a comment in the box below. Ask a Question or Answer a Question.




Share this page: What’s this?

Recent Articles

  1. 5th Grade Factors and Multiples | Definitions | Solved Examples | Math

    Mar 23, 25 02:39 PM

    Prime Factor of 312
    Here we will discuss how factors and multiples are related to each other in math. A factor of a number is a divisor which divides the dividend exactly. A factor of a number which is a prime number is…

    Read More

  2. Adding 2-Digit Numbers | Add Two Two-Digit Numbers without Carrying

    Mar 23, 25 12:43 PM

    Adding 2-Digit Numbers Using an Abacus
    Here we will learn adding 2-digit numbers without regrouping and start working with easy numbers to get acquainted with the addition of two numbers.

    Read More

  3. Worksheet on 12 Times Table | Printable Multiplication Table | Video

    Mar 23, 25 10:28 AM

    worksheet on multiplication of 12 times table
    Worksheet on 12 times table can be printed out. Homeschoolers can also use these multiplication table sheets to practice at home.

    Read More

  4. Vertical Subtraction | Examples | Word Problems| Video |Column Method

    Mar 22, 25 05:20 PM

    Vertical Subtraction
    Vertical subtraction of 1-digit number are done by arranging the numbers column wise i.e., one number under the other number. How to subtract 1-digit number vertically?

    Read More

  5. Worksheet on 11 Times Table | Printable Multiplication Table | Video

    Mar 22, 25 05:08 PM

    worksheet on multiplication of 11 times table
    Worksheet on 11 times table can be printed out. Homeschoolers can also use these multiplication table sheets to practice at home.

    Read More