№1

<RSU = 180⁰ - <RUS - <URS = 180⁰ - 83⁰ - 48⁰ = 49⁰

<UST = <RSU = 49⁰

<SUT = 180⁰ - RUS = 180⁰ - 83⁰ = 97⁰

<STU = 180⁰ - <SUT - <UST = 180⁰ - 97⁰ - 49⁰ = 34⁰

№2

<DEG = 180⁰ - <GDE - <DGE = 180⁰ - 45⁰ - 95⁰ = 40⁰

<GEF = 4/5 DGE = 4/5 × 95⁰ = 76⁰

<EGF = 180⁰ - <F - <GEF = 180⁰ - 80⁰ - 76⁰ = 24⁰

Сумма углов треугольника DEGF.

<D + <F + <DEG + <GEF + <EGF + <DGE =

= 45⁰ + 80⁰ + 40⁰ + 76⁰ + 24⁰ + 95⁰ = 360⁰