Question

Which equation could be used to find the perimeter of an isosceles triangle, with two sides 13 cm long, a base 10 cm long and a height of 12 cm?


A.


P = (10 × 12) ÷ 2


B.


P = 2 × 13 + 10


C.


P = 13 + 10 + 12


D.


P = 2 × 10 + 13

Answer 1

B

Answer 2

5, 12, 13 is a special triangle

Answer 3

what does 5, 12, 13 have to do with the question?

Answer 4

5 is half the base length

Answer 5

so perimeter = 13 + 13 + 5(2)

Answer 6

which is the same as 2 × 13 + 10

Answer 7

and what about the 12 though? where does that come in? sorry just a bit confused

Answer 8

lol it's okay. that's why i mentioned the 5, 12, 13 special triangle, whenever u see at the least 2 of these 3 numbers, the other remaining side will have the length of the remaining 1 number. so in this case, would be half the triangle

Answer 9

ah, that makes sense... and we know that we can do that since the question told us that 12 was the height so that it makes a right angle... got it. thanks :)

Answer 10

lol yes no problem mate :D