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I used to be able to do these myself, but I embarassingly forgot how to.


a. Calculate ∠B

b. Calculate the length of EF in the triangle DEF

c. Calculate ∠GHJ in the square GHIJ

d. How long are the diagonals in square GHIJ

e. Calculate ∠HSI

 Apr 18, 2019
edited by HeyxJacq  Apr 18, 2019

Remember SOHCAHTOA for right triangles?

a) Cos (B) = 8/17       now do th einverse cos to find B

b) Sin 20 = ?/11          Can you do it now?

c)Tan GHJ = 10/3

d) Pythagorean theorem   DIagonal = sqrt (10^2 + 3^2)

e) draw line from S to bisect side 10    then  1/2  Diagonal is hypotenuse  and one leg is 5     then calculate the top angle....which is 1/2 of angle HSI


See what you find!   cheeky

 Apr 18, 2019

Hi thanks for the reply! But I'm super confused at your answer for b. Shouldn't it be 11*tan(20) instead of sinus? 

Guest Apr 21, 2019

EP's answer for (b) is correct.....we know the hypotenuse.....and an angle....and we are looking for the side opposite the angle


The sine  relates the   opp side  / hypotenuse



cool cool cool

CPhill  Apr 21, 2019

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