Respuesta :
Given that ABC is a right angle triangle with m∠C=90°, m∠B=75° and AB=12cm.
Area of triangle =
=
So we need to find BC,AC now.
To find them let us take sinB and cosB.
SinB =
BC = 12* cos B = 12* cos 75
So, area =
= 72*sin(75)*cos(75)
= 36*(2sin(75)cos(75))
= 36*sin(150) = 18
Hence area of triangle is 18
Hope this helps tbh sorry I was a little late btw (:
The area of the given right-angle is 18 cm².
What is a right-angle triangle?
A right-angle triangle is a triangle that has a right angle as an interior angle.
Given, right △ABC with m∠C=90°, m∠B=75°, and AB = 12 cm.
Therefore, sin (∠B) = [tex]\frac{AC}{AB}[/tex]
⇒ sin(75°) = [tex]\frac{AC}{12}[/tex]
⇒ AC = 12 × sin(75°)
⇒ AC = 12 × 0.966
⇒ AC = 11.59 cm
Again, tan(∠B) = [tex]\frac{AC}{BC}[/tex]
⇒ tan(75°) = [tex]\frac{11.59}{BC}[/tex]
⇒ 3.732 = [tex]\frac{11.59}{BC}[/tex]
⇒ BC = [tex]\frac{11.59}{3.732}[/tex] cm = 3.105 cm
Therefore, area of the ΔABC
= [tex]\frac{1}{2}[/tex] × AC × BC
= [tex]\frac{1}{2}[/tex] × 11.59 × 3.105 cm²
= 18 cm²
Learn more about a right-angle triangle here: https://brainly.com/question/11108818
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