where: r is the side opposite angle R q is the side opposite angle Q p is the side opposite angle P
First, label the triangle.
Next, rewrite the Area formula based on the given values of the triangle.
The formula needs two sides and one angle in between them (included angle).
The included angle, P, is missing, but we can find it knowing that the sum of all interior angles in a triangle is 180°. Subtract the other 2 known angles from 180°.
180−(65+42)=180−107=73°
A△=12rqsinP
Finally, substitute the values to the revised formula and solve for the area.
r=22cm
q=29cm
P=73°
A△
=
12rqsinP
=
12(22)(29)sin73°
Substitute the values
=
12(638)sin73°
Evaluate sin73 on your calculator
=
319×0.9563
=
305.06cm2
Rounded off to 2 decimal places
305.06cm2
Question 4 of 4
4. Question
Find the area of the non-right angled triangle below.
k is the side opposite angle K l is the side opposite angle L
First, label the triangle.
Next, rewrite the Area formula based on the given values of the triangle.
The formula needs two sides and one angle in between them (included angle).
The included angle, J, is missing, but we can find it knowing that the sum of all interior angles in a triangle is 180°. Subtract the other 2 known angles from 180°.
180−(38+79)=180−117=63°
A△=12klsinJ
Finally, substitute the values to the revised formula and solve for the area.