Trig practice
HARDSTONE AND KOFFEE BAR CAFES
assessment practice Test
28th February 2023
Demonstrate at least 2 different skills. For example,
(1) using the cosine rule to calculate an angle given 3 lengths.
(2) calculating the area of one triangle using the sine area formula.
Towards Merit, repeat the cosine rule to find angle B in the first triangle. Angle C is found using the 180⁰ rule.
Now for the second triangle (window), work out angle D at the top using the 180⁰ rule.
(1) using the cosine rule to calculate an angle given 3 lengths.
(2) calculating the area of one triangle using the sine area formula.
Towards Merit, repeat the cosine rule to find angle B in the first triangle. Angle C is found using the 180⁰ rule.
Now for the second triangle (window), work out angle D at the top using the 180⁰ rule.
HARDSTONE CAFE
1) angle A = cos¯¹((24^2+25^2-23^2)/(2x24x25))=55.94⁰
2) area = 0.5x24x25xsin(55.94)=248.54m²
3) angle B = cos¯¹((23^2+25^2-24^2)/(2x23x25))=59.83⁰
4) angle C = 180-(55.94+59.83)=64.23⁰
KOFFEE BAR
1) angle D = 180-(76+68)=36⁰
2) length AD 25xsin(68)/sin(36)=39.44m
3) length DB 25xsin(76)/sin(36)=41.27m
4) Area ADB 0.5x39.44x25xsin(76)=478.36m²
1) angle A = cos¯¹((24^2+25^2-23^2)/(2x24x25))=55.94⁰
2) area = 0.5x24x25xsin(55.94)=248.54m²
3) angle B = cos¯¹((23^2+25^2-24^2)/(2x23x25))=59.83⁰
4) angle C = 180-(55.94+59.83)=64.23⁰
KOFFEE BAR
1) angle D = 180-(76+68)=36⁰
2) length AD 25xsin(68)/sin(36)=39.44m
3) length DB 25xsin(76)/sin(36)=41.27m
4) Area ADB 0.5x39.44x25xsin(76)=478.36m²