Waste less time on Facebook — follow Brilliant.
×

Find out right the area???????

ABC is a isosceles triangle whose AB=AC=10cm. the angle BAC is 30 degrees. Find out the area of the triangle. ????

Note by Rahul Das
4 years ago

No vote yet
1 vote

Comments

Sort by:

Top Newest

Use the sine formula for the area of the triangle. \([ABC]=\frac{1}{2}(AB)(AC) \sin A\).

Jaydee Lucero - 4 years ago

Log in to reply

by using this formula: Area=1/2(AB)(AC)sinA. area=1/2(10)(10)1/2=25 cm^2

Log in to reply

area=1/21010*sin30=25 cm^2

Nasir Mehmood Alam - 4 years ago

Log in to reply

Using cosine law you will determine BC.After that using hero's formula you will determine the area of triangle

Edsel Salariosa - 4 years ago

Log in to reply

25cm^2 as the formula is (1/2)(10)(10)(sin 30)=25 (sin 30 =1/2)

Divyansh Singhal - 4 years ago

Log in to reply

Or, if you don't want trigonometry, draw \(AD\) perpendicular to \(BC\) at \(D\). Since angles \(B\) and \(C\) both measure 75 degrees, you have no choice, but to use the ratio \(\frac{AD}{AB}=\frac{AD}{AC}=\frac{\sqrt{2}+\sqrt{6}}{4}\) which still comes from trigonometry.

Jaydee Lucero - 4 years ago

Log in to reply

×

Problem Loading...

Note Loading...

Set Loading...