Maths GCSE homework

[Ladyface]

Help! DD and I can’t work this final question out. It’s really bugging me.

Each interior angle is 108⁰ as its a regular pentagon so you know one angle in the triangle they've made is 108⁰. Angles in a triangle add up to 180 so 180 - 108 = 72. 72/2 = 36 so angle x = 36⁰. (I think; it's a while since I did angle work)

Totally agree with dementedpixie's answer.

I also agree with dementedpixie.

(To explain the 108 degree comment though: a regular pentagon can be split up into three separate triangles with no crossing lines (try drawing the lines!). Each of these triangles contains 180 degrees. Thus, the internal angles at each corner of the pentagon must measure 3*180/5=108.)

Thank you so much! That boggled my brain but it makes sense now.