# If Angle a and Angle B Are Acute Angles Such that Cos a = Cos B, Then Show that Angle a = Angle B. - Mathematics

If ∠A and ∠B are acute angles such that cos A = cos B, then show that ∠A = ∠B.

#### Solution

∠A and ∠B are acute angles

Cos A = cos B S.T ∠A = ∠B

Let us consider right angled triangle ACB.

We have cos A = "adjacent side"/"Hypotenuse"

= (AC)/(AB)

cos B = (BC)/(AB)

cos A = cos B

(AC)/(AB) = (BC)/(AB)

AC = BC

∠A = ∠B

Is there an error in this question or solution?

#### APPEARS IN

RD Sharma Class 10 Maths
Chapter 10 Trigonometric Ratios
Exercise 10.1 | Q 33 | Page 25