In △ABC, AB = 13.2m, BC = 6.9m and ∠ACB = 90°. H lies on AC such that
∠BHC = 46°. Find

(i) ∠ABH

(ii) The length of AH

(i) ∠ABH  = 14.5°

(ii) The length of AH = 4.6 m

Step-by-step explanation:

To solve the problem, we will follow the steps below;

(i)Finding  ∠ABH

first lets find <HBC

<BHC + <HBC + <BCH  = 180°  (Sum of interior angle in a polygon)

46° + <HBC  + 90 = 180°

 <HBC+ 136°  = 180°

subtract 136 from both-side of the equation

 <HBC+ 136° - 136°  = 180° -136°

 <HBC  = 44°

lets find <ABC

To do that, we need to first find <BAC

Using the sine rule

=  

A = ?

a=6.9

C=90

c=13.2

=

sin A = 6.9 sin 90  /13.2

sinA = 0.522727

A = sin⁻¹ ( 0.522727)

A ≈ 31.5 °

<BAC  = 31.5°

<BAC + <ABC + <BCA = 180° (sum of interior angle of a triangle)

31.5° +<ABC + 90° = 180°

<ABC  + 121.5°  = 180°

subtract 121.5° from both-side of the equation

<ABC  + 121.5° - 121.5°  = 180° - 121.5°

<ABC = 58.5°

<ABH = <ABC - <HBC

           =58.5° - 44°

            =14.5°

∠ABH = 14.5°

(ii) Finding the length of AH

To find length AH, we need to first find ∠AHB

<AHB + <BHC = 180°  ( angle on a straight line)

<AHB + 46° = 180°

subtract 46° from both-side of the equation

<AHB + 46°- 46° = 180° - 46°

<AHB  = 134°

Using sine rule,

 =

AH = 13.2 sin 14.5 / sin 134

AH≈4.6 m

length AH = 4.6 m