Math Problem Statement

In the given figure, side QR is produced to a point S. If the bisectors of angle PQR angle PRS and meet at point T. Then the value of angle TRS , when angle QPR =110 and ,angle TQS= 1/5 angle QTR is: class 9 correct ans

Solution

To solve the problem, we need to use some properties of angles, particularly focusing on angle bisectors and relationships between angles in the triangle.

Given:

  • QPR=110\angle QPR = 110^\circ
  • TQS=15×QTR\angle TQS = \frac{1}{5} \times \angle QTR

Step 1: Identify Known Angles

First, let’s denote some of the angles with variables to make our work easier.

  • Let PQR=x\angle PQR = x.
  • Since QRQR is extended to SS, PRS=180x\angle PRS = 180^\circ - x.
  • Since TT is the intersection of the angle bisectors of PQR\angle PQR and PRS\angle PRS, the properties of angle bisectors will be crucial.

Step 2: Use the Relationship Given in the Problem

We know that: TQS=15×QTR\angle TQS = \frac{1}{5} \times \angle QTR Since TT lies on the angle bisectors, TQS\angle TQS and QTR\angle QTR are related to the angles of the triangle. Specifically: TQS=PQR/2=x2\angle TQS = \angle PQR/2 = \frac{x}{2} QTR=PRS/2=180x2\angle QTR = \angle PRS/2 = \frac{180^\circ - x}{2} Given TQS=15×QTR\angle TQS = \frac{1}{5} \times \angle QTR: x2=15×180x2\frac{x}{2} = \frac{1}{5} \times \frac{180^\circ - x}{2} Multiply both sides by 2 to eliminate the denominator: x=15×(180x)x = \frac{1}{5} \times (180^\circ - x) Multiply through by 5: 5x=180x5x = 180^\circ - x Add xx to both sides: 6x=1806x = 180^\circ Divide by 6: x=30x = 30^\circ So, PQR=30\angle PQR = 30^\circ.

Step 3: Find TRS\angle TRS

Now, PRS\angle PRS is: PRS=180PQR=18030=150\angle PRS = 180^\circ - \angle PQR = 180^\circ - 30^\circ = 150^\circ

Since TT is the bisector: TRS=1502=75\angle TRS = \frac{150^\circ}{2} = 75^\circ

Thus, the value of TRS\angle TRS is 7575^\circ.

Would you like more details or have any questions?

Related Questions:

  1. What is the sum of all angles in a triangle?
  2. How do angle bisectors affect the angles in a triangle?
  3. What is the relationship between the exterior angle and the interior opposite angles?
  4. How does extending a side of a triangle affect the adjacent angle?
  5. Can the sum of angles on a straight line be used to solve any triangle problem?

Tip:

Always double-check your work when dealing with angle bisectors, as small errors in identifying or calculating angles can lead to incorrect conclusions.

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Math Problem Analysis

Mathematical Concepts

Geometry
Angles
Angle Bisectors

Formulas

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Theorems

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Suitable Grade Level

Class 9