As the annual exam for all class 9 students of CBSE will be held in February/March 2020, this is the time when they should start making effective preparations with help of authentic and reliable study resources. Especially, for Maths, they should practice with a good set of questions. Here, in this article, we are providing important 3 marks questions with solutions to prepare for the CBSE class 9 Mathematics annual exam 2020. By practicing these important questions, students can get an idea about the important topics and also assess their preparedness for the final exam. This will help them to fine-tune their preparation.

In CBSE Class 9 Mathematics Exam 2020, Section - C will comprise 8 questions of 3 marks each.

All the questions given here have been picked from the most important topics of class 9 Maths. All these questions have been provided with the detailed solutions to help students make their exam preparations easily and effectively.

**Given below are some sample questions for CBSE Class 9 Mathematics: Important 3 Marks Questions:**

**Q.** In a figure ABC is an equilateral triangle. The coordinates of vertices B and C are (3,0) and (-3,0) respectively. Find the coordinates of its vertex A.

**Solution.**

Given coordinates of B and C are (-4, 0) and (4, 0)

Draw AD perpendicular to BC

and CO = OB = 4 units

Hence O coincides with the origin.

Since ABC is an equilateral triangle, AB = BC = CA = 8 units

In right triangle AOC, AC^{2 }= AO^{2} + OC^{2} [By Pythagoras theorem]

⟹ 8^{2} = AO^{2} + 4^{2}

⟹ AO^{2 }= 64 – 16 = 48

⟹ AO = √48 units

Hence the coordinates of A are (0, √48).

**CBSE Class 9 Maths Chapter-wise Important Topics and Questions**

**Q.** Suman spins two spinners, one of which is labeled 1, 2 and 3 and the other are labeled A, B, C and D. Find the probability of:

(i) Stopping at 2 and C.

(ii) Stopping at 3 and either B or D

(iii) Stopping at any number and A

**Solution.**

Sample space = {A1, A2, A3, B1, B2, B3, C1, C2, C3, D1, D2, D3}

Total possible outcome = 12

Probability of stopping at 2 and C = 1/12

Probability of stopping at 3 and either B or D = 2/12 = 1/6

Probability of stopping at any number and A = 3/12 = 1/4

**CBSE Class 9 Mathematics Practice Papers**

**Q.** Construct an angle of 135^{o} at the initial point of a given ray and justify the construction.

**Solution.**

**Steps of construction: **

1. Draw a ray OA.

2. With its initial point O as centre and any radius, draw an arc BE, cutting OA and its produced part at C and E respectively.

3. With centre B and same radius (as in step 2), draw an arc, cutting the arc BE at C.

4. With C as centre and the same radius, draw an arc cutting the arc BE at D.

5. With C and D as centres, and any convenient radius (more than 1/2 CD), draw two arcs intersecting at P.

6. Join OP.

Then ∠AOP = ∠EOP = 90^{o}

7. Draw OQ as the bisector of ∠EOP.

Then, ∠AOQ =135^{o}

**Justification :**

By construction ∠AOP = 90^{o}

Thus, ∠AOP = ∠EOP = 90^{o}

Also, OQ is drawn as the bisector of ∠EOP

Therefore, ∠POQ =1/2∠EOP =1/2 × 90^{o} = 45^{o}

Thus, ∠AOQ = ∠AOP + ∠POQ = 90^{o} + 45^{o} = 135^{o}

Hence justified.

**To get the complete set of questions, click on the following link:**

**Also Check:**

**CBSE Class 9 Mathematics Exam 2018: Important 1 Mark Questions**

**CBSE Class 9 Mathematics Exam 2018: Important 2 Marks Questions**

**Students may also check the following links to explore more stuff, important for CBSE Class 9 Annual exam preparations:**