A P6 Math Question
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A PSLE Prelim question from one of the top 10 primary schools.
The triangle ABC is an isosceles triangle.
Find the area of the triangle ABC.
A
l \
l***\
l*****\
l******\ 12 cm
l********\
l_********\
l_l______\ C
B -
since isoc, the other 2 angle is 45 degree.
hence, find the height
area of triangle is h x b x half.
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claps claps claps
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Hi Skythewood,
Your answer is not correct. The question requires the answer to be an actual number in cm^2. Please take note that the given length of AC is 12 cm. The solving of this question does not require the use of Pythagoras Theorem as it is a PSLE maths question.
Thank you for your kind attention.
Regards,
ahm97sic
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Simple.
Anyway your diagram don't look like isosceles triangle.
Draw 4 triangles = 1 square
Area of square = 12 x 12 = 144
Area of 1 triangle = 1/4 x 144 = 36
Hope that answers your question.
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Originally posted by maurizio13:
Simple.
Anyway your diagram don't look like isosceles triangle.
Draw 4 triangles = 1 square
Area of square = 12 x 12 = 144
Area of 1 triangle = 1/4 x 144 = 36
Hope that answers your question.
Since the angles are 45, 45, 90, that's why you can draw 3 more triangles to form a 12 by 12 square. From there, divide by four.
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Originally posted by Ahm97sic:
Hi Skythewood,
Your answer is not correct. The question requires the answer to be an actual number in cm^2. Please take note that the given length of AC is 12 cm. The solving of this question does not require the use of Pythagoras Theorem as it is a PSLE maths question.
Thank you for your kind attention.
Regards,
ahm97sic
ooo.. cannot use pythygoras theorem ah.
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Hi Skythewood,
Maurizio13 did not use the Pythagoras Theorem to solve the question. He drew a square of side 12 cm on the side AC. When the area of this square is divided into 4 equal triangles, the area of each triangle is 144/4 = 36 cm^2. The area of one triangle is the same as the area of the triangle ABC, so the area of the triangle ABC is 36 cm^2.
Thank you for your kind attention.
Regards,
ahm97sic
PS : Maurizio13, sorry for the drawing of the triangle. It is not possible to draw or type mathematical signs in the forum.
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Originally posted by Ahm97sic:
Hi Skythewood,
Maurizio13 did not use the Pythagoras Theorem to solve the question. He drew a square of side 12 cm on the side AC. When the area of this square is divided into 4 equal triangles, the area of each triangle is 144/4 = 36 cm^2. The area of one triangle is the same as the area of the triangle ABC, so the area of the triangle ABC is 36 cm^2.
Thank you for your kind attention.
Regards,
ahm97sic
PS : Maurizio13, sorry for the drawing of the triangle. It is not possible to draw or type mathematical signs in the forum.
i think my previous post went gibblish, but nvm...
your primary 6 kid will probably use AC=12 cm as base, and draw a line down to find the height. cos they are kids, only know h x b x half.
after drawing the line down, they will realised they have cut the triangle to 2 halves, look at the left half, it is a isoc. triangle! so by isoc. triangle rule, the height is 6 cm.
than apply back the h x b x half.
so solve question by drawing one line, not by drawing 3 more triangle.
sorry about the gliblish that was posted.