where: rr is the side opposite angle RR qq is the side opposite angle QQ pp is the side opposite angle PP
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, PP, is missing, but we can find it knowing that the sum of all interior angles in a triangle is 180°180°. Subtract the other 22 known angles from 180°180°.
180-(65+42)=180-107=180−(65+42)=180−107=73°73°
A△=12A△=12rrqqsinsinPP
Finally, substitute the values to the revised formula and solve for the area.
r=22r=22cm
q=29q=29cm
P=73°P=73°
A△A△
==
1212rrqqsinsinPP
==
12(12(2222)()(2929)sin)sin73°73°
Substitute the values
==
12(638)sin73°12(638)sin73°
Evaluate sinsin7373 on your calculator
==
319×0.9563319×0.9563
==
305.06cm2305.06cm2
Rounded off to 22 decimal places
305.06cm2305.06cm2
Question 4 of 4
4. Question
Find the area of the non-right angled triangle below.
kk is the side opposite angle KK ll is the side opposite angle LL
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, JJ, is missing, but we can find it knowing that the sum of all interior angles in a triangle is 180°180°. Subtract the other 22 known angles from 180°180°.
180-(38+79)=180-117=180−(38+79)=180−117=63°63°
A△=12A△=12kkllsinsinJJ
Finally, substitute the values to the revised formula and solve for the area.