Extra Questions For Class 10 Maths Trigonometry | Q7

CBSE Chapter 8 | Trigonometric Ratios of Specific values

This CBSE class 10 Maths extra question is from the topic Trigonometry. Concept Covered: Calculating trigonometric ratios of specific values.

Question 7: In triangle ABC right angled at B, AB = 12cm and ∠CAB = 60°. Determine the lengths of the other two sides.


Target Centum in CBSE 10th Maths


Free Online CBSE Coaching
online.maxtute.com

Video Explanation


NCERT Solution to Class 10 Maths


With Videos


Explanatory Answer | Trigonometry Extra Question 7

Δ ABC is right angled at B
AB = 12 cm and ∠CAB = 60 °

2020 CBSE Class 10 Trigonometry Q7 Triangle

Part 1: Compute Length of AC

Let us use the trigonometric ratio involving AB and AC.
To angle ∠CAB, AB is the adjacent side.
AC is the hypotenuse of the triangle.
So, we will use cos ∠CAB.
cos ∠CAB = cos 60° = \\frac{\text{AB}}{\text{AC}})
cos 60° = \\frac{\text{1}}{\text{2}})
∴ \\frac{\text{1}}{\text{2}}) = \\frac{\text{12}}{\text{AC}})
AC = 2 × 12 = 24 cm
So, AC = 24 cm

Part 2: Calculate Length of BC

Let us use the trigonometric ratio involving AB and BC.
To angle ∠CAB, AB is the adjacent side and BC is the opposite side.
So, we will use tan ∠CAB
tan ∠CAB = tan 60 ° = \\frac{\text{BC}}{\text{AB}})
tan 60° = √3
√3 =\\frac{\text{BC}}{\text{12}})
BC = 12 × √3 cm

CBSE Online Coaching | Class 10 Maths - Trigonometry Extra Practice Questions


WhatsApp: WhatsApp Now
Email: learn@maxtute.com