Can someone help me please? Thanks!

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1 Answer
Sep 22, 2017

see below

Explanation:

The property of an isosceles triangle we need to consider is that the height of the triangle is the perpendicular bisector of the base.

so we have two right angled triangles withe the base as 18ft

(a) when theta=45^0

tan45=y/18

color(blue)(y=18xxtan45=18xx1=18ft)

(b) when theta=55^0

tan55=y/18

color(red)(y=18xxtan55=25.71(2dp))

using a calculator

(c) we want to find the areas in both cases

A_(Delta)=1/2xx"base "xx"heigt"

for case (a)

A_(Deltaa)=1/2xx18xx18

color(blue)(A_(Deltaa)=162 ft^2)

case (b)

A_(Deltab)=1/2xx18xx25.71

color(red)(A_(Deltab)=231.39ft^2(2dp))